Broadcast signal transmitting apparatus, broadcast signal receiving apparatus, broadcast signal transmitting method, and broadcast signal receiving method

ABSTRACT

Disclosed is a method for transmitting a broadcast signal. The method comprises formatting input streams with multiple data transmission channels, and the formatting step comprises adding a header indicating a format of a payload of the BBF.

This application claims priority to Provisional Application No.62/075,898 filed on 6 Nov. 2014 in US, and Provisional Application No.62/080,382 filed on 16 Nov. 2014 in US the entire contents of which ishereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a broadcast signal transmittingapparatus, a broadcast signal receiving apparatus, and broadcast signaltransmitting and receiving methods.

2. Discussion of Related Art

As transmission of an analog broadcast signal ends, various techniquesfor transmitting and receiving a digital broadcast signal have beendeveloped. The digital broadcast signal can include more video/audiodata than the analog broadcast signal and further include various kindsof additional data as well as the video/audio data.

SUMMARY OF THE INVENTION

That is, a digital broadcasting system may provide a high definition(HD) image, a multi channel audio, and various additional services.However, for digital broadcasting, data transmission efficiency fortransmission of more data, robustness of a transmission and receptionnetwork, network flexibility considering a mobile receiving apparatusneed to be improved.

Further, an object of the present invention is to provide a method forsignaling existence of a stuffing field in a BBF.

In addition, another object of the present invention is to provide amethod for designating the stuffing field that exists in the BBF, thatis, a use type of stuffing data.

Moreover, yet another object of the present invention is to provideefficient use of a stuffing type field by dividing and using a stuffingtype field into two different fields.

Technical objects to be achieved by the present specification are notlimited to the aforementioned technical objects and other unmentionedtechnical objects will be clearly understood by those skilled in the artfrom the following description.

In accordance with an embodiment of the present invention, a method fortransmitting a broadcast signal, the method comprising: formatting inputstreams into multiple data transmission channels; encoding datacorresponding to each of data transmission channel carrying service dataor service component data; building at least one signal frame comprisingthe encoded data; modulating the at least one signal frame by an OFDM(orthogonal frequency division multiplexing) scheme; and transmittingthe broadcast signal comprising the at least one modulated signal frame,wherein the formatting comprises adding a header indicating a format ofa payload of a baseband frame (BBF), and wherein the header comprises acontrol information indicating whether a stuffing field is present inthe header.

The header may include at least one of indication information indicatingwhether a most significant bit (MSB) part of a stuffing length ispresent in the stuffing field or a stuffing type (STUFF_TYPE) fieldindicating a type of stuffing data.

The stuffing field may include a stuffing header and stuffing data, andthe indication information and the stuffing type field may be includedin the stuffing header.

The size of the indication information may be 1 bit, and the size of thestuffing type (STUFF_TYPE) field may be 2 bits.

The stuffing header may further include a stuffing length (STUFF_LEN)field indicating the length of the stuffing field, and the stuffinglength (STUFF_LEN) field may be divided into a MSB (STUFF_LEN_MSB) partof the stuffing length and an LSB (STUFF_LEN_LSB) part of the stuffinglength.

The control information may be an extension indicator (EXT_I) field, andthe indication information may be an MSB_I (indicator) field.

The stuffing field may be included in the baseband frame when thepayload is not filled with a data packet or in-band signaling is used.

The stuffing data may indicate at least one of stuffing or in-bandsignaling.

When the length of the stuffing field is 32 bytes or less, the MSB partof the stuffing length may not be included in the stuffing field.

In accordance with another embodiment of the present invention, anapparatus for transmitting a broadcast signal, the apparatus comprising:an input formatter for formatting input streams into multiple datatransmission channels; an encoder for encoding data corresponding toeach of data transmission channel which carrying service data or servicecomponent data; a frame builder for building at least one signal framecomprising the encoded data; a modulator for modulating the at least onesignal frame by an OFDM (orthogonal frequency division multiplexing)scheme; and transmitter for transmitting the broadcast signal comprisingthe at least one modulated signal frame, wherein the input formattercomprises a baseband frame header inserter for adding a headerindicating a format of a payload of a baseband frame (BBF), and whereinthe header comprises a control information indicating whether a stuffingfield is present in the header.

The present invention can provide various broadcasting services bycontrolling a quality of service (QoS) for each service or servicecomponent by processing data according to a service characteristic.

Further, according to the present invention, transmission flexibilitycan be achieved by transmitting various broadcasting services throughthe same radio frequency (RF) signal bandwidth.

In addition, according to the present invention, data transmissionefficiency and transmission and reception robustness of a broadcastsignal can be improved by using a multiple-input multiple-output (MIMO)system.

Besides, according to the present invention, broadcast signaltransmitting and receiving methods and apparatuses can be provided,which can receive a digital broadcast signal by using a mobile receivingapparatus or without an error in spite of an indoor environment.

According to the present invention, whether a stuffing field in a BBFexists can be rapidly and accurately known by defining a new fieldindicating whether the stuffing field exists in the BBF.

Other information can be used in the stuffing field in addition tostuffing by defining the stuffing field that exists in the BBF, that is,a use type of stuffing data.

Moreover, a stuffing type field can be efficiently operated by dividingand using a stuffing type field into two different fields.

Effects to be acquired by the present invention are not limited to theaforementioned effects and other unmentioned effects will be clearlyunderstood by those skilled in the art from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings included to more appreciate the presentinvention and included in the present application, and constituting apart thereof illustrate embodiments of the present invention togetherwith a detailed description for describing a principle the presentinvention.

FIG. 1 illustrates a structure of a broadcast signal transmittingapparatus for a next-generation broadcasting service according to anexemplary embodiment of the present invention.

FIGS. 2(a) and (b) illustrate an input formatting block according to anexemplary embodiment of the present invention.

FIG. 3 illustrates an input formatting block according to anotherexemplary embodiment of the present invention.

FIG. 4 illustrates an input formatting block according to yet anotherexemplary embodiment of the present invention.

FIGS. 5(a) and (b) illustrate a bit interleaved coding & modulation(BICM) block according to an exemplary embodiment of the presentinvention.

FIG. 6 illustrates a BICM block according to another exemplaryembodiment of the present invention.

FIG. 7 illustrates a frame building block according to an exemplaryembodiment of the present invention.

FIG. 8 illustrates an orthogonal frequency division multiplexing (OFDM)generation block according to an exemplary embodiment of the presentinvention.

FIG. 9 illustrates a structure of a broadcast signal receiving apparatusfor a next-generation broadcasting service according to an exemplaryembodiment of the present invention.

FIGS. 10(a), (b), (c) and (d) illustrate frame structures according toan exemplary embodiment of the present invention.

FIG. 11 illustrates a signaling layer structure of a frame structureaccording to an exemplary embodiment of the present invention.

FIG. 12 illustrates preamble signaling data according to an exemplaryembodiment of the present invention.

FIG. 13 illustrates PLS1 data according to an exemplary embodiment ofthe present invention.

FIG. 14 illustrates PLS2 data according to an exemplary embodiment ofthe present invention.

FIG. 15 illustrates PLS2 data according to another exemplary embodimentof the present invention.

FIG. 16 illustrates a logical structure of a frame according to anexemplary embodiment of the present invention.

FIG. 17 illustrates physical layer signaling (PLS) mapping according toan exemplary embodiment of the present invention.

FIG. 18 illustrates emergency alert channel (EAC) mapping according toan exemplary embodiment of the present invention.

FIGS. 19(a) and (b) illustrate fast information channel (FIC) mappingaccording to an exemplary embodiment of the present invention.

FIGS. 20(a) and (b) illustrate a type of data pipe (DP) according to anexemplary embodiment of the present invention.

FIGS. 21(a) and (b) illustrate a type of data pipe (DP) mappingaccording to an exemplary embodiment of the present invention.

FIG. 22 illustrates forward error correction (FEC) structure accordingto an exemplary embodiment of the present invention.

FIG. 23 illustrates bit interleaving according to an exemplaryembodiment of the present invention.

FIGS. 24(a) and (b) illustrate cell-word demultiplexing according anexemplary embodiment of the present invention.

FIGS. 25(a), (b) and (c) illustrate time interleaving according to anexemplary embodiment of the present invention.

FIGS. 26(a) and (b) illustrate a basic operation of a twisted row-columnblock interleaver according to an exemplary embodiment of the presentinvention.

FIG. 27 illustrates an operation of a twisted row-column blockinterleaver according to another exemplary embodiment of the presentinvention.

FIG. 28 illustrates a diagonal reading pattern of the twisted row-columnblock interleaver according to the exemplary embodiment of the presentinvention.

FIG. 29 illustrates XFECBLOCK interleaved from each interleaving arrayaccording to an exemplary embodiment of the present invention.

FIG. 30 is a diagram illustrating one example of a synchronization anddemodulation module of FIG. 9.

FIG. 31 is a diagram illustrating one example of a frame parsing moduleof FIG. 9.

FIGS. 32A, 32B, 32C and 32D are diagrams illustrating examples of ademapping and decoding module of FIG. 9.

FIG. 33 is a diagram illustrating one example of one example of anoutput processor of FIG. 9.

FIGS. 34A and 34B are diagrams illustrating another example of theoutput processor of FIG. 9.

FIGS. 35A, 35B, 35C and 35D illustrate a coding and modulation moduleaccording to another exemplary embodiment of the present invention.

FIGS. 36A, 36B, 36C and 36D are diagram illustrating a demapping anddecoding module according to another exemplary embodiment of the presentinvention.

FIG. 37 is a diagram illustrating one example of a mode adaptationmodule proposed in the specification.

FIG. 38 is a diagram illustrating one example of an output processorproposed in the specification.

FIG. 39 is a diagram illustrating one example of a BB frame structure inthe related art.

FIG. 40 is a diagram illustrating another example of the BB framestructure in the related art.

FIG. 41 is a diagram illustrating yet another example of the BB framestructure in the related art.

FIG. 42 illustrates one example of a BB frame structure proposed in thespecification.

FIGS. 43(a), (b), (c), (d) (e) and (f) are diagrams illustrating anotherexample of the BB frame structure proposed in the specification.

FIG. 44 is a diagram illustrating yet another example of the BB framestructure proposed in the specification.

FIGS. 45(a), (b), (c), (d), (e) and (f) are diagrams illustrating stillanother example of the BB frame structure proposed in the specification.

FIG. 46 is a diagram illustrating comparison of a result of calculatingoverhead for transmission of a BB frame in various BB frame structures.

FIG. 47 illustrates one example of a BB frame structure in the relatedart.

FIG. 48 is a diagram illustrating an example of a BB frame structureproposed in the specification.

FIG. 49 is a diagram illustrating another example of the BB framestructure proposed in the specification.

FIG. 50 is a diagram illustrating yet another example of the BB framestructure proposed in the specification.

FIG. 51 is a diagram illustrating still another example of the BB framestructure proposed in the specification.

FIG. 52 is a flowchart illustrating one example of a method fortransmitting a broadcast signal proposed in the specification.

FIG. 53 is a flowchart illustrating one example of a broadcast signalreceiving method proposed in the specification.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. The detailed description, which will be given below withreference to the accompanying drawings, is intended to explain exemplaryembodiments of the present invention, rather than to show the onlyembodiments that can be implemented according to the present invention.The following detailed description includes specific details in order toprovide a thorough understanding of the present invention. However, itwill be apparent to those skilled in the art that the present inventionmay be practiced without such specific details.

Although most terms used in the present invention have been selectedfrom general ones widely used in the art, some terms have beenarbitrarily selected by the applicant and their meanings are explainedin detail in the following description as needed. Thus, the presentinvention should be understood based upon the intended meanings of theterms rather than their simple names or meanings.

The present invention provides apparatuses and methods for transmittingand receiving broadcast signals for future broadcast services. Futurebroadcast services according to an embodiment of the present inventioninclude a terrestrial broadcast service, a mobile broadcast service, aUHDTV service, etc. The present invention may process broadcast signalsfor the future broadcast services through non-MIMO (Multiple InputMultiple Output) or MIMO according to one embodiment. A non-MIMO schemeaccording to an embodiment of the present invention may include a MISO(Multiple Input Single Output) scheme, a SISO (Single Input SingleOutput) scheme, etc.

While MISO or MIMO uses two antennas in the following for convenience ofdescription, the present invention is applicable to systems using two ormore antennas.

The present invention may defines three physical layer (PL)profiles—base, handheld and advanced profiles—each optimized to minimizereceiver complexity while attaining the performance required for aparticular use case. The physical layer (PHY) profiles are subsets ofall configurations that a corresponding receiver should implement.

The three PHY profiles share most of the functional blocks but differslightly in specific blocks and/or parameters. Additional PHY profilescan be defined in the future. For the system evolution, future profilescan also be multiplexed with the existing profiles in a single RFchannel through a future extension frame (FEF). The details of each PHYprofile are described below.

1. Base Profile

The base profile represents a main use case for fixed receiving devicesthat are usually connected to a roof-top antenna. The base profile alsoincludes portable devices that could be transported to a place butbelong to a relatively stationary reception category. Use of the baseprofile could be extended to handheld devices or even vehicular by someimproved implementations, but those use cases are not expected for thebase profile receiver operation.

Target SNR range of reception is from approximately 10 to 20 dB, whichincludes the 15 dB SNR reception capability of the existing broadcastsystem (e.g. ATSC A/53). The receiver complexity and power consumptionis not as critical as in the battery-operated handheld devices, whichwill use the handheld profile. Key system parameters for the baseprofile are listed in below table 1.

TABLE 1 LDPC codeword length 16K, 64K bits Constellation size 4~10 bpcu(bits per channel use) Time de-interleaving memory size ≦2¹⁹ data cellsPilot patterns Pilot pattern for fixed reception FFT size 16K, 32Kpoints

2. Handheld Profile

The handheld profile is designed for use in handheld and vehiculardevices that operate with battery power. The devices can be moving withpedestrian or vehicle speed. The power consumption as well as thereceiver complexity is very important for the implementation of thedevices of the handheld profile. The target SNR range of the handheldprofile is approximately 0 to 10 dB, but can be configured to reachbelow 0 dB when intended for deeper indoor reception.

In addition to low SNR capability, resilience to the Doppler Effectcaused by receiver mobility is the most important performance attributeof the handheld profile. Key system parameters for the handheld profileare listed in the below table 2.

TABLE 2 LDPC codeword length 16K bits Constellation size 2~8 bpcu Timede-interleaving memory size ≦2¹⁸ data cells Pilot patterns Pilotpatterns for mobile and indoor reception FFT size 8K, 16K points

3. Advanced Profile

The advanced profile provides highest channel capacity at the cost ofmore implementation complexity. This profile requires using MIMOtransmission and reception, and UHDTV service is a target use case forwhich this profile is specifically designed. The increased capacity canalso be used to allow an increased number of services in a givenbandwidth, e.g., multiple SDTV or HDTV services.

The target SNR range of the advanced profile is approximately 20 to 30dB. MIMO transmission may initially use existing elliptically-polarizedtransmission equipment, with extension to full-power cross-polarizedtransmission in the future. Key system parameters for the advancedprofile are listed in below table 3.

TABLE 3 LDPC codeword length 16K, 64K bits Constellation size 8~12 bpcuTime de-interleaving memory size ≦2¹⁹ data cells Pilot patterns Pilotpattern for fixed reception FFT size 16K, 32K points

In this case, the base profile can be used as a profile for both theterrestrial broadcast service and the mobile broadcast service. That is,the base profile can be used to define a concept of a profile whichincludes the mobile profile. Also, the advanced profile can be dividedadvanced profile for a base profile with MIMO and advanced profile for ahandheld profile with MIMO. Moreover, the three profiles can be changedaccording to intention of the designer.

The following terms and definitions may apply to the present invention.The following terms and definitions can be changed according to design.

auxiliary stream: sequence of cells carrying data of as yet undefinedmodulation and coding, which may be used for future extensions or asrequired by broadcasters or network operators

base data pipe: data pipe that carries service signaling data

baseband frame (or BBFRAME): set of Kbch bits which form the input toone FEC encoding process (BCH and LDPC encoding)

cell: modulation value that is carried by one carrier of the OFDMtransmission

coded block: LDPC-encoded block of PLS1 data or one of the LDPC-encodedblocks of PLS2 data

data pipe: logical channel in the physical layer that carries servicedata or related metadata, which may carry one or multiple service(s) orservice component(s).

data pipe unit: a basic unit for allocating data cells to a DP in aframe.

data symbol: OFDM symbol in a frame which is not a preamble symbol (theframe signaling symbol and frame edge symbol is included in the datasymbol)

DP_ID: this 8-bit field identifies uniquely a DP within the systemidentified by the SYSTEM_ID

dummy cell: cell carrying a pseudo-random value used to fill theremaining capacity not used for PLS signaling, DPs or auxiliary streams

emergency alert channel: part of a frame that carries EAS informationdata

frame: physical layer time slot that starts with a preamble and endswith a frame edge symbol

frame repetition unit: a set of frames belonging to same or differentphysical layer profile including a FEF, which is repeated eight times ina super-frame

fast information channel: a logical channel in a frame that carries themapping information between a service and the corresponding base DP

FECBLOCK: set of LDPC-encoded bits of a DP data

FFT size: nominal FFT size used for a particular mode, equal to theactive symbol period Ts expressed in cycles of the elementary period T

frame signaling symbol: OFDM symbol with higher pilot density used atthe start of a frame in certain combinations of FFT size, guard intervaland scattered pilot pattern, which carries a part of the PLS data

frame edge symbol: OFDM symbol with higher pilot density used at the endof a frame in certain combinations of FFT size, guard interval andscattered pilot pattern

frame-group: the set of all the frames having the same PHY profile typein a super-frame.

future extension frame: physical layer time slot within the super-framethat could be used for future extension, which starts with a preamble

Futurecast UTB system: proposed physical layer broadcasting system, ofwhich the input is one or more MPEG2-TS or IP or general stream(s) andof which the output is an RF signal

input stream: A stream of data for an ensemble of services delivered tothe end users by the system.

normal data symbol: data symbol excluding the frame signaling symbol andthe frame edge symbol

PHY profile: subset of all configurations that a corresponding receivershould implement

PLS: physical layer signaling data consisting of PLS1 and PLS2

PLS1: a first set of PLS data carried in the FSS symbols having a fixedsize, coding and modulation, which carries basic information about thesystem as well as the parameters needed to decode the PLS2

NOTE: PLS1 data remains constant for the duration of a frame-group.

PLS2: a second set of PLS data transmitted in the FSS symbol, whichcarries more detailed PLS data about the system and the DPs

PLS2 dynamic data: PLS2 data that may dynamically change frame-by-frame

PLS2 static data: PLS2 data that remains static for the duration of aframe-group

preamble signaling data: signaling data carried by the preamble symboland used to identify the basic mode of the system

preamble symbol: fixed-length pilot symbol that carries basic PLS dataand is located in the beginning of a frame

NOTE: The preamble symbol is mainly used for fast initial band scan todetect the system signal, its timing, frequency offset, and FFT-size.

reserved for future use: not defined by the present document but may bedefined in future

super-frame: set of eight frame repetition units

time interleaving block (TI block): set of cells within which timeinterleaving is carried out, corresponding to one use of the timeinterleaver memory

TI group: unit over which dynamic capacity allocation for a particularDP is carried out, made up of an integer, dynamically varying number ofXFECBLOCKs

NOTE: The TI group may be mapped directly to one frame or may be mappedto multiple frames. It may contain one or more TI blocks.

Type 1 DP: DP of a frame where all DPs are mapped into the frame in TDMfashion

Type 2 DP: DP of a frame where all DPs are mapped into the frame in FDMfashion

XFECBLOCK: set of Ncells cells carrying all the bits of one LDPCFECBLOCK

FIG. 1 illustrates a structure of an apparatus for transmittingbroadcast signals for future broadcast services according to anembodiment of the present invention.

The apparatus for transmitting broadcast signals for future broadcastservices according to an embodiment of the present invention can includean input formatting block 1000, a BICM (Bit interleaved coding &modulation) block 1010, a frame structure block 1020, an OFDM(Orthogonal Frequency Division Multiplexing) generation block 1030 and asignaling generation block 1040. A description will be given of theoperation of each module of the apparatus for transmitting broadcastsignals.

The input formatting block 1000 can be represented to an inputformatter.

The BICM (Bit interleaved coding & modulation) block 1010 can berepresented to an encoder.

The frame structure block 1020 can be represented to a frame builder.

The OFDM (Orthogonal Frequency Division Multiplexing) generation block1030 can be represented to a modulator.

IP stream/packets and MPEG2-TS are the main input formats, other streamtypes are handled as General Streams. In addition to these data inputs,Management Information is input to control the scheduling and allocationof the corresponding bandwidth for each input stream. One or multiple TSstream(s), IP stream(s) and/or General Stream(s) inputs aresimultaneously allowed.

The input formatting block 1000 can demultiplex each input stream intoone or multiple data pipe(s), to each of which an independent coding andmodulation is applied. The data pipe (DP) is the basic unit forrobustness control, thereby affecting quality-of-service (QoS). One ormultiple service(s) or service component(s) can be carried by a singleDP. Details of operations of the input formatting block 1000 will bedescribed later.

The data pipe is a logical channel in the physical layer that carriesservice data or related metadata, which may carry one or multipleservice(s) or service component(s).

The data pipe can be represented to a data transmission channel.

Also, the data pipe unit: a basic unit for allocating data cells to a DPin a frame.

In the BICM block 1010, parity data is added for error correction andthe encoded bit streams are mapped to complex-value constellationsymbols. The symbols are interleaved across a specific interleavingdepth that is used for the corresponding DP. For the advanced profile,MIMO encoding is performed in the BICM block 1010 and the additionaldata path is added at the output for MIMO transmission. Details ofoperations of the BICM block 1010 will be described later.

The Input Formatting Block of FIG. 1 implements functions, processes,and/or methods proposed in FIGS. 50, 51, and 52 to be described below.

The Frame Building block 1020 can map the data cells of the input DPsinto the OFDM symbols within a frame. After mapping, the frequencyinterleaving is used for frequency-domain diversity, especially tocombat frequency-selective fading channels. Details of operations of theFrame Building block 1020 will be described later.

After inserting a preamble at the beginning of each frame, the OFDMGeneration block 1030 can apply conventional OFDM modulation having acyclic prefix as guard interval. For antenna space diversity, adistributed MISO scheme is applied across the transmitters. In addition,a Peak-to-Average Power Reduction (PAPR) scheme is performed in the timedomain. For flexible network planning, this proposal provides a set ofvarious FFT sizes, guard interval lengths and corresponding pilotpatterns. Details of operations of the OFDM Generation block 1030 willbe described later.

The Signaling Generation block 1040 can create physical layer signalinginformation used for the operation of each functional block. Thissignaling information is also transmitted so that the services ofinterest are properly recovered at the receiver side. Details ofoperations of the Signaling Generation block 1040 will be describedlater.

FIGS. 2, 3 and 4 illustrate the input formatting block 1000 according toembodiments of the present invention. A description will be given ofeach figure.

The Input Formatting Block of FIG. 2 to FIG. 4 implements functions,processes, and/or methods proposed in FIGS. 50, 51, and 52 to bedescribed below.

FIG. 2 illustrates an input formatting block according to one embodimentof the present invention. FIG. 2 shows an input formatting module whenthe input signal is a single input stream.

The input formatting block illustrated in FIG. 2 corresponds to anembodiment of the input formatting block 1000 described with referenceto FIG. 1.

The input to the physical layer may be composed of one or multiple datastreams. Each data stream is carried by one DP. The mode adaptationmodules slice the incoming data stream into data fields of the basebandframe

(BBF). The system supports three types of input data streams: MPEG2-TS,Internet protocol (IP) and Generic stream (GS). MPEG2-TS ischaracterized by fixed length (188 byte) packets with the first bytebeing a sync-byte (0x47). An IP stream is composed of variable length IPdatagram packets, as signaled within IP packet headers. The systemsupports both IPv4 and IPv6 for the IP stream. GS may be composed ofvariable length packets or constant length packets, signaled withinencapsulation packet headers.

(a) shows a mode adaptation block 2000 and a stream adaptation 2010 forsignal DP and (b) shows a PLS generation block 2020 and a PLS scrambler2030 for generating and processing PLS data. A description will be givenof the operation of each block.

The Input Stream Splitter splits the input TS, IP, GS streams intomultiple service or service component (audio, video, etc.) streams. Themode adaptation module 2010 is comprised of a CRC Encoder, BB (baseband)Frame Slicer, and BB Frame Header Insertion block.

The CRC Encoder provides three kinds of CRC encoding for error detectionat the user packet (UP) level, i.e., CRC-8, CRC-16, and CRC-32. Thecomputed CRC bytes are appended after the UP. CRC-8 is used for TSstream and CRC-32 for IP stream. If the GS stream doesn't provide theCRC encoding, the proposed CRC encoding should be applied.

BB Frame Slicer maps the input into an internal logical-bit format. Thefirst received bit is defined to be the MSB. The BB Frame Slicerallocates a number of input bits equal to the available data fieldcapacity. To allocate a number of input bits equal to the BBF payload,the UP packet stream is sliced to fit the data field of BBF.

BB Frame Header Insertion block can insert fixed length BBF header of 2bytes is inserted in front of the BB Frame. The BBF header is composedof STUFFI (1 bit), SYNCD (13 bits), and RFU (2 bits). In addition to thefixed 2-Byte BBF header, BBF can have an extension field (1 or 3 bytes)at the end of the 2-byte BBF header.

The stream adaptation 2010 is comprised of stuffing insertion block andBB scrambler.

The stuffing insertion block can insert stuffing field into a payload ofa BB frame. If the input data to the stream adaptation is sufficient tofill a BB-Frame, STUFFI is set to ‘0’ and the BBF has no stuffing field.Otherwise STUFFI is set to ‘1’ and the stuffing field is insertedimmediately after the BBF header. The stuffing field comprises two bytesof the stuffing field header and a variable size of stuffing data.

The BB scrambler scrambles complete BBF for energy dispersal. Thescrambling sequence is synchronous with the BBF. The scrambling sequenceis generated by the feed-back shift register.

The PLS generation block 2020 can generate physical layer signaling(PLS) data. The PLS provides the receiver with a means to accessphysical layer DPs. The PLS data consists of PLS1 data and PLS2 data.

The PLS1 data is a first set of PLS data carried in the FSS symbols inthe frame having a fixed size, coding and modulation, which carriesbasic information about the system as well as the parameters needed todecode the PLS2 data. The PLS1 data provides basic transmissionparameters including parameters required to enable the reception anddecoding of the PLS2 data. Also, the PLS1 data remains constant for theduration of a frame-group.

The PLS2 data is a second set of PLS data transmitted in the FSS symbol,which carries more detailed PLS data about the system and the DPs. ThePLS2 contains parameters that provide sufficient information for thereceiver to decode the desired DP. The PLS2 signaling further consistsof two types of parameters, PLS2 Static data (PLS2-STAT data) and PLS2dynamic data (PLS2-DYN data). The PLS2 Static data is PLS2 data thatremains static for the duration of a frame-group and the PLS2 dynamicdata is PLS2 data that may dynamically change frame-by-frame.

Details of the PLS data will be described later.

The PLS scrambler 2030 can scramble the generated PLS data for energydispersal.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions.

FIG. 3 illustrates an input formatting block according to anotherembodiment of the present invention.

The input formatting block illustrated in FIG. 3 corresponds to anembodiment of the input formatting block 1000 described with referenceto FIG. 1.

FIG. 3 shows a mode adaptation block of the input formatting block whenthe input signal corresponds to multiple input streams.

The mode adaptation block of the input formatting block for processingthe multiple input streams can independently process the multiple inputstreams.

Referring to FIG. 3, the mode adaptation block for respectivelyprocessing the multiple input streams can include an input streamsplitter 3000, an input stream synchronizer 3010, a compensating delayblock 3020, a null packet deletion block 3030, a head compression block3040, a CRC encoder 3050, a BB frame slicer 3060 and a BB headerinsertion block 3070. Description will be given of each block of themode adaptation block.

Operations of the CRC encoder 3050, BB frame slicer 3060 and BB headerinsertion block 3070 correspond to those of the CRC encoder, BB frameslicer and BB header insertion block described with reference to FIG. 2and thus description thereof is omitted.

The input stream splitter 3000 can split the input TS, IP, GS streamsinto multiple service or service component (audio, video, etc.) streams.

The input stream synchronizer 3010 may be referred as ISSY. The ISSY canprovide suitable means to guarantee Constant Bit Rate (CBR) and constantend-to-end transmission delay for any input data format. The ISSY isalways used for the case of multiple DPs carrying TS, and optionallyused for multiple DPs carrying GS streams.

The compensating delay block 3020 can delay the split TS packet streamfollowing the insertion of ISSY information to allow a TS packetrecombining mechanism without requiring additional memory in thereceiver.

The null packet deletion block 3030, is used only for the TS inputstream case. Some TS input streams or split TS streams may have a largenumber of null-packets present in order to accommodate VBR (variablebit-rate) services in a CBR TS stream. In this case, in order to avoidunnecessary transmission overhead, null-packets can be identified andnot transmitted. In the receiver, removed null-packets can bere-inserted in the exact place where they were originally by referenceto a deleted null-packet (DNP) counter that is inserted in thetransmission, thus guaranteeing constant bit-rate and avoiding the needfor time-stamp (PCR) updating.

The head compression block 3040 can provide packet header compression toincrease transmission efficiency for TS or IP input streams. Because thereceiver can have a priori information on certain parts of the header,this known information can be deleted in the transmitter.

For Transport Stream, the receiver has a-priori information about thesync-byte configuration (0x47) and the packet length (188 Byte). If theinput TS stream carries content that has only one PID, i.e., for onlyone service component (video, audio, etc.) or service sub-component (SVCbase layer, SVC enhancement layer, MVC base view or MVC dependentviews), TS packet header compression can be applied (optionally) to theTransport Stream. IP packet header compression is used optionally if theinput steam is an IP stream.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions.

FIG. 4 illustrates an input formatting block according to anotherembodiment of the present invention.

The input formatting block illustrated in FIG. 4 corresponds to anembodiment of the input formatting block 1000 described with referenceto FIG. 1.

FIG. 4 illustrates a stream adaptation block of the input formattingmodule when the input signal corresponds to multiple input streams.

Referring to FIG. 4, the mode adaptation block for respectivelyprocessing the multiple input streams can include a scheduler 4000, an1-Frame delay block 4010, a stuffing insertion block 4020, an in-bandsignaling 4030, a BB Frame scrambler 4040, a PLS generation block 4050and a PLS scrambler 4060. Description will be given of each block of thestream adaptation block.

Operations of the stuffing insertion block 4020, the BB Frame scrambler4040, the PLS generation block 4050 and the PLS scrambler 4060correspond to those of the stuffing insertion block, BB scrambler, PLSgeneration block and the PLS scrambler described with reference to FIG.2 and thus description thereof is omitted.

The scheduler 4000 can determine the overall cell allocation across theentire frame from the amount of FECBLOCKs of each DP. Including theallocation for PLS, EAC and FIC, the scheduler generate the values ofPLS2-DYN data, which is transmitted as in-band signaling or PLS cell inFSS of the frame. Details of FECBLOCK, EAC and FIC will be describedlater.

The 1-Frame delay block 4010 can delay the input data by onetransmission frame such that scheduling information about the next framecan be transmitted through the current frame for in-band signalinginformation to be inserted into the DPs.

The in-band signaling 4030 can insert un-delayed part of the PLS2 datainto a DP of a frame.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions.

FIG. 5 illustrates a BICM block according to an embodiment of thepresent invention.

The BICM block illustrated in FIG. 5 corresponds to an embodiment of theBICM block 1010 described with reference to FIG. 1.

As described above, the apparatus for transmitting broadcast signals forfuture broadcast services according to an embodiment of the presentinvention can provide a terrestrial broadcast service, mobile broadcastservice, UHDTV service, etc.

Since QoS (quality of service) depends on characteristics of a serviceprovided by the apparatus for transmitting broadcast signals for futurebroadcast services according to an embodiment of the present invention,data corresponding to respective services needs to be processed throughdifferent schemes. Accordingly, the a BICM block according to anembodiment of the present invention can independently process DPs inputthereto by independently applying SISO, MISO and MIMO schemes to thedata pipes respectively corresponding to data paths. Consequently, theapparatus for transmitting broadcast signals for future broadcastservices according to an embodiment of the present invention can controlQoS for each service or service component transmitted through each DP.

(a) shows the BICM block shared by the base profile and the handheldprofile and (b) shows the BICM block of the advanced profile.

The BICM block shared by the base profile and the handheld profile andthe BICM block of the advanced profile can include plural processingblocks for processing each DP.

A description will be given of each processing block of the BICM blockfor the base profile and the handheld profile and the BICM block for theadvanced profile.

A processing block 5000 of the BICM block for the base profile and thehandheld profile can include a Data FEC encoder 5010, a bit interleaver5020, a constellation mapper 5030, an SSD (Signal Space Diversity)encoding block 5040 and a time interleaver 5050.

The Data FEC encoder 5010 can perform the FEC encoding on the input BBFto generate FECBLOCK procedure using outer coding (BCH), and innercoding (LDPC). The outer coding (BCH) is optional coding method. Detailsof operations of the Data FEC encoder 5010 will be described later.

The bit interleaver 5020 can interleave outputs of the Data FEC encoder5010 to achieve optimized performance with combination of the LDPC codesand modulation scheme while providing an efficiently implementablestructure. Details of operations of the bit interleaver 5020 will bedescribed later.

The constellation mapper 5030 can modulate each cell word from the bitinterleaver 5020 in the base and the handheld profiles, or cell wordfrom the Cell-word demultiplexer 5010-1 in the advanced profile usingeither QPSK, QAM-16, non-uniform QAM (NUQ-64, NUQ-256, NUQ-1024) ornon-uniform constellation (NUC-16, NUC-64, NUC-256, NUC-1024) to give apower-normalized constellation point, el. This constellation mapping isapplied only for DPs. Observe that QAM-16 and NUQs are square shaped,while NUCs have arbitrary shape. When each constellation is rotated byany multiple of 90 degrees, the rotated constellation exactly overlapswith its original one. This “rotation-sense” symmetric property makesthe capacities and the average powers of the real and imaginarycomponents equal to each other. Both NUQs and NUCs are definedspecifically for each code rate and the particular one used is signaledby the parameter DP_MOD filed in PLS2 data.

The SSD encoding block 5040 can precode cells in two (2D), three (3D),and four (4D) dimensions to increase the reception robustness underdifficult fading conditions.

The time interleaver 5050 can operates at the DP level. The parametersof time interleaving (TI) may be set differently for each DP. Details ofoperations of the time interleaver 5050 will be described later.

A processing block 5000-1 of the BICM block for the advanced profile caninclude the Data FEC encoder, bit interleaver, constellation mapper, andtime interleaver. However, the processing block 5000-1 is distinguishedfrom the processing block 5000 further includes a cell-worddemultiplexer 5010-1 and a MIMO encoding block 5020-1.

Also, the operations of the Data FEC encoder, bit interleaver,constellation mapper, and time interleaver in the processing block5000-1 correspond to those of the Data FEC encoder 5010, bit interleaver5020, constellation mapper 5030, and time interleaver 5050 described andthus description thereof is omitted.

The cell-word demultiplexer 5010-1 is used for the DP of the advancedprofile to divide the single cell-word stream into dual cell-wordstreams for MIMO processing. Details of operations of the cell-worddemultiplexer 5010-1 will be described later.

The MIMO encoding block 5020-1 can processing the output of thecell-word demultiplexer 5010-1 using MIMO encoding scheme. The MIMOencoding scheme was optimized for broadcasting signal transmission. TheMIMO technology is a promising way to get a capacity increase but itdepends on channel characteristics. Especially for broadcasting, thestrong LOS component of the channel or a difference in the receivedsignal power between two antennas caused by different signal propagationcharacteristics makes it difficult to get capacity gain from MIMO. Theproposed MIMO encoding scheme overcomes this problem using arotation-based pre-coding and phase randomization of one of the MIMOoutput signals.

MIMO encoding is intended for a 2×2 MIMO system requiring at least twoantennas at both the transmitter and the receiver. Two MIMO encodingmodes are defined in this proposal; full-rate spatial multiplexing(FR-SM) and full-rate full-diversity spatial multiplexing (FRFD-SM). TheFR-SM encoding provides capacity increase with relatively smallcomplexity increase at the receiver side while the FRFD-SM encodingprovides capacity increase and additional diversity gain with a greatcomplexity increase at the receiver side. The proposed MIMO encodingscheme has no restriction on the antenna polarity configuration.

MIMO processing is required for the advanced profile frame, which meansall DPs in the advanced profile frame are processed by the MIMO encoder.MIMO processing is applied at DP level. Pairs of the ConstellationMapper outputs NUQ (e1,i and e2,i) are fed to the input of the MIMOEncoder. Paired MIMO Encoder output (g1,i and g2,i) is transmitted bythe same carrier k and OFDM symbol l of their respective TX antennas.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions.

FIG. 6 illustrates a BICM block according to another embodiment of thepresent invention.

The BICM block illustrated in FIG. 6 corresponds to an embodiment of theBICM block 1010 described with reference to FIG. 1.

FIG. 6 illustrates a BICM block for protection of physical layersignaling (PLS), emergency alert channel (EAC) and fast informationchannel (FIC). EAC is a part of a frame that carries EAS informationdata and FIC is a logical channel in a frame that carries the mappinginformation between a service and the corresponding base DP. Details ofthe EAC and FIC will be described later.

Referring to FIG. 6, the BICM block for protection of PLS, EAC and FICcan include a PLS FEC encoder 6000, a bit interleaver 6010, aconstellation mapper 6020 and time interleaver 6030.

Also, the PLS FEC encoder 6000 can include a scrambler, BCHencoding/zero insertion block, LDPC encoding block and LDPC paritypuncturing block. Description will be given of each block of the BICMblock.

The PLS FEC encoder 6000 can encode the scrambled PLS 1/2 data, EAC andFIC section.

The scrambler can scramble PLS1 data and PLS2 data before BCH encodingand shortened and punctured LDPC encoding.

The BCH encoding/zero insertion block can perform outer encoding on thescrambled PLS 1/2 data using the shortened BCH code for PLS protectionand insert zero bits after the BCH encoding. For PLS1 data only, theoutput bits of the zero insertion may be permutted before LDPC encoding.

The LDPC encoding block can encode the output of the BCH encoding/zeroinsertion block using LDPC code. To generate a complete coded block,Cldpc, parity bits, Pldpc are encoded systematically from eachzero-inserted PLS information block, Ildpc and appended after it.

C _(ldpc) =[I _(ldpc) P _(ldpc) ]=[i ₀ ,i ₁ , . . . ,i _(K) _(ldpc) ₋₁,p ₀ ,p ₁ , . . . ,p _(N) _(ldpc) _(-K) _(ldpc) ₋₁]  [Math figure 1]

The LDPC code parameters for PLS1 and PLS2 are as following table 4.

TABLE 4 Signaling Kldpc code Type Ksig Kbch Nbch_parity (=Nbch) NldpcNldpc_parity rate Qldpc PLS1 342 1020 60 1080 4320 3240 1/4  36 PLS2<1021 >1020 2100 2160 7200 5040 3/10 56

The LDPC parity puncturing block can perform puncturing on the PLS1 dataand PLS 2 data.

When shortening is applied to the PLS1 data protection, some LDPC paritybits are punctured after LDPC encoding. Also, for the PLS2 dataprotection, the LDPC parity bits of PLS2 are punctured after LDPCencoding. These punctured bits are not transmitted.

The bit interleaver 6010 can interleave the each shortened and puncturedPLS1 data and PLS2 data.

The constellation mapper 6020 can map the bit interleaved PLS1 data andPLS2 data onto constellations.

The time interleaver 6030 can interleave the mapped PLS1 data and PLS2data.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions.

FIG. 7 illustrates a frame building block according to one embodiment ofthe present invention.

The frame building block illustrated in FIG. 7 corresponds to anembodiment of the frame building block 1020 described with reference toFIG. 1.

Referring to FIG. 7, the frame building block can include a delaycompensation block 7000, a cell mapper 7010 and a frequency interleaver7020. Description will be given of each block of the frame buildingblock.

The delay compensation block 7000 can adjust the timing between the datapipes and the corresponding PLS data to ensure that they are co-timed atthe transmitter end. The PLS data is delayed by the same amount as datapipes are by addressing the delays of data pipes caused by the InputFormatting block and BICM block. The delay of the BICM block is mainlydue to the time interleaver 5050. In-band signaling data carriesinformation of the next TI group so that they are carried one frameahead of the DPs to be signaled. The Delay Compensating block delaysin-band signaling data accordingly.

The cell mapper 7010 can map PLS, EAC, FIC, DPs, auxiliary streams anddummy cells into the active carriers of the OFDM symbols in the frame.The basic function of the cell mapper 7010 is to map data cells producedby the TIs for each of the DPs, PLS cells, and EAC/FIC cells, if any,into arrays of active OFDM cells corresponding to each of the OFDMsymbols within a frame. Service signaling data (such as PSI (programspecific information)/SI) can be separately gathered and sent by a datapipe. The Cell Mapper operates according to the dynamic informationproduced by the scheduler and the configuration of the frame structure.Details of the frame will be described later.

The frequency interleaver 7020 can randomly interleave data cellsreceived from the cell mapper 7010 to provide frequency diversity. Also,the frequency interleaver 7020 can operate on very OFDM symbol paircomprised of two sequential OFDM symbols using a differentinterleaving-seed order to get maximum interleaving gain in a singleframe. Details of operations of the frequency interleaver 7020 will bedescribed later.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions.

FIG. 8 illustrates an OFMD generation block according to an embodimentof the present invention.

The OFMD generation block illustrated in FIG. 8 corresponds to anembodiment of the OFMD generation block 1030 described with reference toFIG. 1.

The OFDM generation block modulates the OFDM carriers by the cellsproduced by the Frame Building block, inserts the pilots, and producesthe time domain signal for transmission. Also, this block subsequentlyinserts guard intervals, and applies PAPR (Peak-to-Average Power Radio)reduction processing to produce the final RF signal.

Referring to FIG. 8, the frame building block can include a pilot andreserved tone insertion block 8000, a 2D-eSFN encoding block 8010, anIFFT (Inverse Fast Fourier Transform) block 8020, a PAPR reduction block8030, a guard interval insertion block 8040, a preamble insertion block8050, other system insertion block 8060 and a DAC block 8070.Description will be given of each block of the frame building block.

The pilot and reserved tone insertion block 8000 can insert pilots andthe reserved tone.

Various cells within the OFDM symbol are modulated with referenceinformation, known as pilots, which have transmitted values known apriori in the receiver. The information of pilot cells is made up ofscattered pilots, continual pilots, edge pilots, FSS (frame signalingsymbol) pilots and FES (frame edge symbol) pilots. Each pilot istransmitted at a particular boosted power level according to pilot typeand pilot pattern. The value of the pilot information is derived from areference sequence, which is a series of values, one for eachtransmitted carrier on any given symbol. The pilots can be used forframe synchronization, frequency synchronization, time synchronization,channel estimation, and transmission mode identification, and also canbe used to follow the phase noise.

Reference information, taken from the reference sequence, is transmittedin scattered pilot cells in every symbol except the preamble, FSS andFES of the frame. Continual pilots are inserted in every symbol of theframe. The number and location of continual pilots depends on both theFFT size and the scattered pilot pattern. The edge carriers are edgepilots in every symbol except for the preamble symbol. They are insertedin order to allow frequency interpolation up to the edge of thespectrum. FSS pilots are inserted in FSS(s) and FES pilots are insertedin FES. They are inserted in order to allow time interpolation up to theedge of the frame.

The system according to an embodiment of the present invention supportsthe SFN network, where distributed MISO scheme is optionally used tosupport very robust transmission mode. The 2D-eSFN is a distributed MISOscheme that uses multiple TX antennas, each of which is located in thedifferent transmitter site in the SFN network.

The 2D-eSFN encoding block 8010 can process a 2D-eSFN processing todistorts the phase of the signals transmitted from multipletransmitters, in order to create both time and frequency diversity inthe SFN configuration. Hence, burst errors due to low flat fading ordeep-fading for a long time can be mitigated.

The IFFT block 8020 can modulate the output from the 2D-eSFN encodingblock 8010 using OFDM modulation scheme. Any cell in the data symbolswhich has not been designated as a pilot (or as a reserved tone) carriesone of the data cells from the frequency interleaver. The cells aremapped to OFDM carriers.

The PAPR reduction block 8030 can perform a PAPR reduction on inputsignal using various PAPR reduction algorithm in the time domain.

The guard interval insertion block 8040 can insert guard intervals andthe preamble insertion block 8050 can insert preamble in front of thesignal. Details of a structure of the preamble will be described later.The other system insertion block 8060 can multiplex signals of aplurality of broadcast transmission/reception systems in the time domainsuch that data of two or more different broadcast transmission/receptionsystems providing broadcast services can be simultaneously transmittedin the same RF signal bandwidth. In this case, the two or more differentbroadcast transmission/reception systems refer to systems providingdifferent broadcast services. The different broadcast services may referto a terrestrial broadcast service, mobile broadcast service, etc. Datarelated to respective broadcast services can be transmitted throughdifferent frames.

The DAC block 8070 can convert an input digital signal into an analogsignal and output the analog signal. The signal output from the DACblock 7800 can be transmitted through multiple output antennas accordingto the physical layer profiles. A Tx antenna according to an embodimentof the present invention can have vertical or horizontal polarity.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions according to design.

FIG. 9 illustrates a structure of an apparatus for receiving broadcastsignals for future broadcast services according to an embodiment of thepresent invention.

The apparatus for receiving broadcast signals for future broadcastservices according to an embodiment of the present invention cancorrespond to the apparatus for transmitting broadcast signals forfuture broadcast services, described with reference to FIG. 1.

The apparatus for receiving broadcast signals for future broadcastservices according to an embodiment of the present invention can includea synchronization & demodulation module 9000, a frame parsing module9010, a demapping & decoding module 9020, an output processor 9030 and asignaling decoding module 9040. A description will be given of operationof each module of the apparatus for receiving broadcast signals.

The synchronization & demodulation module 9000 can be represented to areceiver and an OFDM demodulator.

The frame parsing module 9010 can be represented to a frame parser.

The demapping & decoding module 9020 can be represented to a converterand a decoder.

The synchronization & demodulation module 9000 can receive input signalsthrough m Rx antennas, perform signal detection and synchronization withrespect to a system corresponding to the apparatus for receivingbroadcast signals and carry out demodulation corresponding to a reverseprocedure of the procedure performed by the apparatus for transmittingbroadcast signals.

The frame parsing module 9100 can parse input signal frames and extractdata through which a service selected by a user is transmitted. If theapparatus for transmitting broadcast signals performs interleaving, theframe parsing module 9100 can carry out deinterleaving corresponding toa reverse procedure of interleaving. In this case, the positions of asignal and data that need to be extracted can be obtained by decodingdata output from the signaling decoding module 9400 to restorescheduling information generated by the apparatus for transmittingbroadcast signals.

The demapping & decoding module 9200 can convert the input signals intobit domain data and then deinterleave the same as necessary. Thedemapping & decoding module 9200 can perform demapping for mappingapplied for transmission efficiency and correct an error generated on atransmission channel through decoding. In this case, the demapping &decoding module 9200 can obtain transmission parameters necessary fordemapping and decoding by decoding the data output from the signalingdecoding module 9400.

The output processor 9300 can perform reverse procedures of variouscompression/signal processing procedures which are applied by theapparatus for transmitting broadcast signals to improve transmissionefficiency. In this case, the output processor 9300 can acquirenecessary control information from data output from the signalingdecoding module 9400. The output of the output processor 8300corresponds to a signal input to the apparatus for transmittingbroadcast signals and may be MPEG-TSs, IP streams (v4 or v6) and genericstreams.

The signaling decoding module 9400 can obtain PLS information from thesignal demodulated by the synchronization & demodulation module 9000. Asdescribed above, the frame parsing module 9100, demapping & decodingmodule 9200 and output processor 9300 can execute functions thereofusing the data output from the signaling decoding module 9400.

The Output Processor of FIG. 9 implements functions, processes, and/ormethods proposed in FIGS. 50, 51, and 53 to be described below.

FIG. 10 illustrates a frame structure according to an embodiment of thepresent invention.

FIG. 10 shows an example configuration of the frame types and FRUs in asuper-frame. (a) shows a super frame according to an embodiment of thepresent invention, (b) shows FRU (Frame Repetition Unit) according to anembodiment of the present invention, (c) shows frames of variable PHYprofiles in the FRU and (d) shows a structure of a frame.

A super-frame may be composed of eight FRUs. The FRU is a basicmultiplexing unit for TDM of the frames, and is repeated eight times ina super-frame.

Each frame in the FRU belongs to one of the PHY profiles, (base,handheld, advanced) or FEF. The maximum allowed number of the frames inthe FRU is four and a given PHY profile can appear any number of timesfrom zero times to four times in the FRU (e.g., base, base, handheld,advanced). PHY profile definitions can be extended using reserved valuesof the PHY_PROFILE in the preamble, if required.

The FEF part is inserted at the end of the FRU, if included. When theFEF is included in the FRU, the minimum number of FEFs is 8 in asuper-frame. It is not recommended that FEF parts be adjacent to eachother.

One frame is further divided into a number of OFDM symbols and apreamble. As shown in (d), the frame comprises a preamble, one or moreframe signaling symbols (FSS), normal data symbols and a frame edgesymbol (FES).

The preamble is a special symbol that enables fast Futurecast UTB systemsignal detection and provides a set of basic transmission parameters forefficient transmission and reception of the signal. The detaileddescription of the preamble will be will be described later.

The main purpose of the FSS(s) is to carry the PLS data. For fastsynchronization and channel estimation, and hence fast decoding of PLSdata, the FSS has more dense pilot pattern than the normal data symbol.The FES has exactly the same pilots as the FSS, which enablesfrequency-only interpolation within the FES and temporal interpolation,without extrapolation, for symbols immediately preceding the FES.

FIG. 11 illustrates a signaling hierarchy structure of the frameaccording to an embodiment of the present invention.

FIG. 11 illustrates the signaling hierarchy structure, which is splitinto three main parts: the preamble signaling data 11000, the PLS1 data11010 and the PLS2 data 11020. The purpose of the preamble, which iscarried by the preamble symbol in every frame, is to indicate thetransmission type and basic transmission parameters of that frame. ThePLS1 enables the receiver to access and decode the PLS2 data, whichcontains the parameters to access the DP of interest. The PLS2 iscarried in every frame and split into two main parts: PLS2-STAT data andPLS2-DYN data. The static and dynamic portion of PLS2 data is followedby padding, if necessary.

FIG. 12 illustrates preamble signaling data according to an embodimentof the present invention.

Preamble signaling data carries 21 bits of information that are neededto enable the receiver to access PLS data and trace DPs within the framestructure. Details of the preamble signaling data are as follows:

PHY_PROFILE: This 3-bit field indicates the PHY profile type of thecurrent frame. The mapping of different PHY profile types is given inbelow table 5.

TABLE 5 Value PHY profile 000 Base profile 001 Handheld profile 010Advanced profiled 011~110 Reserved 111 FEF

FFT_SIZE: This 2 bit field indicates the FFT size of the current framewithin a frame-group, as described in below table 6.

TABLE 6 Value FFT size 00  8K FFT 01 16K FFT 10 32K FFT 11 Reserved

GI_FRACTION: This 3 bit field indicates the guard interval fractionvalue in the current super-frame, as described in below table 7.

TABLE 7 Value GI_FRACTION 000 ⅕  001 1/10 010 1/20 011 1/40 100 1/80 101  1/160 110~111 Reserved

EAC_FLAG: This 1 bit field indicates whether the EAC is provided in thecurrent frame. If this field is set to ‘1’, emergency alert service(EAS) is provided in the current frame. If this field set to ‘0’, EAS isnot carried in the current frame. This field can be switched dynamicallywithin a super-frame.

PILOT_MODE: This 1-bit field indicates whether the pilot mode is mobilemode or fixed mode for the current frame in the current frame-group. Ifthis field is set to ‘0’, mobile pilot mode is used. If the field is setto ‘1’, the fixed pilot mode is used.

PAPR_FLAG: This 1-bit field indicates whether PAPR reduction is used forthe current frame in the current frame-group. If this field is set tovalue ‘1’, tone reservation is used for PAPR reduction. If this field isset to ‘0’, PAPR reduction is not used.

FRU_CONFIGURE: This 3-bit field indicates the PHY profile typeconfigurations of the frame repetition units (FRU) that are present inthe current super-frame. All profile types conveyed in the currentsuper-frame are identified in this field in all preambles in the currentsuper-frame. The 3-bit field has a different definition for eachprofile, as show in below table 8.

TABLE 8 Current Current Current Current PHY_PROFILE = PHY_PROFILE =PHY_PROFILE = PHY_PROFILE = ‘000’ (base) ‘001’ (handheld) ‘010’(advanced) ‘111’ (FEF) FRU_CONFIGURE = Only base Only handheld Onlyadvanced Only FEF 000 profile present profile present profile presentpresent FRU_CONFIGURE = Handheld Base Base Base 1XX profile presentprofile present profile present profile present FRU_CONFIGURE = AdvancedAdvanced Handheld Handheld X1X profile present profile present profilepresent profile present FRU_CONFIGURE = FEF FEF FEF Advanced XX1 presentpresent present profile present

RESERVED: This 7-bit field is reserved for future use.

FIG. 13 illustrates PLS1 data according to an embodiment of the presentinvention.

PLS1 data provides basic transmission parameters including parametersrequired to enable the reception and decoding of the PLS2. As abovementioned, the PLS1 data remain unchanged for the entire duration of oneframe-group. The detailed definition of the signaling fields of the PLS1data are as follows:

PREAMBLE_DATA: This 20-bit field is a copy of the preamble signalingdata excluding the EAC_FLAG.

NUM_FRAME_FRU: This 2-bit field indicates the number of the frames perFRU.

PAYLOAD_TYPE: This 3-bit field indicates the format of the payload datacarried in the frame-group. PAYLOAD_TYPE is signaled as shown in table9.

TABLE 9 Value Payload type 1XX TS stream is transmitted X1X IP stream istransmitted XX1 GS stream is transmitted

NUM_FSS: This 2-bit field indicates the number of FSS symbols in thecurrent frame.

SYSTEM_VERSION: This 8-bit field indicates the version of thetransmitted signal format. The SYSTEM_VERSION is divided into two 4-bitfields, which are a major version and a minor version.

Major version: The MSB four bits of SYSTEM_VERSION field indicate majorversion information. A change in the major version field indicates anon-backward-compatible change. The default value is ‘0000’. For theversion described in this standard, the value is set to ‘0000’.

Minor version: The LSB four bits of SYSTEM_VERSION field indicate minorversion information. A change in the minor version field isbackward-compatible.

CELL_ID: This is a 16-bit field which uniquely identifies a geographiccell in an ATSC network. An ATSC cell coverage area may consist of oneor more frequencies, depending on the number of frequencies used perFuturecast UTB system. If the value of the CELL_ID is not known orunspecified, this field is set to ‘0’.

NETWORK_ID: This is a 16-bit field which uniquely identifies the currentATSC network.

SYSTEM_ID: This 16-bit field uniquely identifies the Futurecast UTBsystem within the ATSC network. The Futurecast UTB system is theterrestrial broadcast system whose input is one or more input streams(TS, IP, GS) and whose output is an RF signal. The Futurecast UTB systemcarries one or more PHY profiles and FEF, if any. The same FuturecastUTB system may carry different input streams and use different RFfrequencies in different geographical areas, allowing local serviceinsertion. The frame structure and scheduling is controlled in one placeand is identical for all transmissions within a Futurecast UTB system.One or more Futurecast UTB systems may have the same SYSTEM_ID meaningthat they all have the same physical layer structure and configuration.

The following loop consists of FRU_PHY_PROFILE, FRU_FRAME_LENGTH,FRU_GI_FRACTION, and RESERVED which are used to indicate the FRUconfiguration and the length of each frame type. The loop size is fixedso that four PHY profiles (including a FEF) are signaled within the FRU.If NUM_FRAME_FRU is less than 4, the unused fields are filled withzeros.

FRU_PHY_PROFILE: This 3-bit field indicates the PHY profile type of the(i+1)th (i is the loop index) frame of the associated FRU. This fielduses the same signaling format as shown in the table 8.

FRU_FRAME_LENGTH: This 2-bit field indicates the length of the (i+1)thframe of the associated FRU. Using FRU_FRAME_LENGTH together withFRU_GI_FRACTION, the exact value of the frame duration can be obtained.

FRU_GI_FRACTION: This 3-bit field indicates the guard interval fractionvalue of the (i+1)th frame of the associated FRU. FRU_GI_FRACTION issignaled according to the table 7.

RESERVED: This 4-bit field is reserved for future use.

The following fields provide parameters for decoding the PLS2 data.

PLS2_FEC_TYPE: This 2-bit field indicates the FEC type used by the PLS2protection. The FEC type is signaled according to table 10. The detailsof the LDPC codes will be described later.

TABLE 10 Contents PLS2 FEC type 00 4K-1/4 and 7K-3/10 LDPC codes 01~11Reserved

PLS2_MOD: This 3-bit field indicates the modulation type used by thePLS2. The modulation type is signaled according to table 11.

TABLE 11 Value PLS2_MODE 000 BPSK 001 QPSK 010 QAM-16 011 NUQ-64 100~111Reserved

PLS2_SIZE_CELL: This 15-bit field indicates Ctotal_partial_block, thesize (specified as the number of QAM cells) of the collection of fullcoded blocks for PLS2 that is carried in the current frame-group. Thisvalue is constant during the entire duration of the current frame-group.

PLS2_STAT_SIZE_BIT: This 14-bit field indicates the size, in bits, ofthe PLS2-STAT for the current frame-group. This value is constant duringthe entire duration of the current frame-group.

PLS2_DYN_SIZE_BIT: This 14-bit field indicates the size, in bits, of thePLS2-DYN for the current frame-group. This value is constant during theentire duration of the current frame-group.

PLS2_REP_FLAG: This 1-bit flag indicates whether the PLS2 repetitionmode is used in the current frame-group. When this field is set to value‘1’, the PLS2 repetition mode is activated. When this field is set tovalue ‘0’, the PLS2 repetition mode is deactivated.

PLS2_REP SIZE_CELL: This 15-bit field indicates Ctotal_partial_block,the size (specified as the number of QAM cells) of the collection ofpartial coded blocks for PLS2 carried in every frame of the currentframe-group, when PLS2 repetition is used. If repetition is not used,the value of this field is equal to 0. This value is constant during theentire duration of the current frame-group.

PLS2_NEXT_FEC_TYPE: This 2-bit field indicates the FEC type used forPLS2 that is carried in every frame of the next frame-group. The FECtype is signaled according to the table 10.

PLS2_NEXT_MOD: This 3-bit field indicates the modulation type used forPLS2 that is carried in every frame of the next frame-group. Themodulation type is signaled according to the table 11.

PLS2_NEXT_REP_FLAG: This 1-bit flag indicates whether the PLS2repetition mode is used in the next frame-group. When this field is setto value ‘1’, the PLS2 repetition mode is activated. When this field isset to value ‘0’, the PLS2 repetition mode is deactivated.

PLS2_NEXT_REP_SIZE_CELL: This 15-bit field indicates Ctotal_full_block,The size (specified as the number of QAM cells) of the collection offull coded blocks for PLS2 that is carried in every frame of the nextframe-group, when PLS2 repetition is used. If repetition is not used inthe next frame-group, the value of this field is equal to 0. This valueis constant during the entire duration of the current frame-group.

PLS2_NEXT_REP_STAT_SIZE_BIT: This 14-bit field indicates the size, inbits, of the PLS2-STAT for the next frame-group. This value is constantin the current frame-group.

PLS2 NEXT_REP_DYN_SIZE_BIT: This 14-bit field indicates the size, inbits, of the PLS2-DYN for the next frame-group. This value is constantin the current frame-group.

PLS2_AP_MODE: This 2-bit field indicates whether additional parity isprovided for PLS2 in the current frame-group. This value is constantduring the entire duration of the current frame-group. The below table12 gives the values of this field. When this field is set to ‘00’,additional parity is not used for the PLS2 in the current frame-group.

TABLE 12 Value PLS2-AP mode 00 AP is not provided 01 AP1 mode 10~11Reserved

PLS2_AP_SIZE_CELL: This 15-bit field indicates the size (specified asthe number of QAM cells) of the additional parity bits of the PLS2. Thisvalue is constant during the entire duration of the current frame-group.

PLS2_NEXT_AP_MODE: This 2-bit field indicates whether additional parityis provided for PLS2 signaling in every frame of next frame-group. Thisvalue is constant during the entire duration of the current frame-group.The table 12 defines the values of this field

PLS2_NEXT_AP_SIZE_CELL: This 15-bit field indicates the size (specifiedas the number of QAM cells) of the additional parity bits of the PLS2 inevery frame of the next frame-group. This value is constant during theentire duration of the current frame-group.

RESERVED: This 32-bit field is reserved for future use.

CRC_32: A 32-bit error detection code, which is applied to the entirePLS1 signaling.

FIG. 14 illustrates PLS2 data according to an embodiment of the presentinvention.

FIG. 14 illustrates PLS2-STAT data of the PLS2 data. The PLS2-STAT dataare the same within a frame-group, while the PLS2-DYN data provideinformation that is specific for the current frame.

The details of fields of the PLS2-STAT data are as follows:

FIC_FLAG: This 1-bit field indicates whether the FIC is used in thecurrent frame-group. If this field is set to ‘1’, the FIC is provided inthe current frame. If this field set to ‘0’, the FIC is not carried inthe current frame. This value is constant during the entire duration ofthe current frame-group.

AUX_FLAG: This 1-bit field indicates whether the auxiliary stream(s) isused in the current frame-group. If this field is set to ‘1’, theauxiliary stream is provided in the current frame. If this field set to‘0’, the auxiliary stream is not carried in the current frame. Thisvalue is constant during the entire duration of current frame-group.

NUM_DP: This 6-bit field indicates the number of DPs carried within thecurrent frame. The value of this field ranges from 1 to 64, and thenumber of DPs is NUM_DP+1.

DP_ID: This 6-bit field identifies uniquely a DP within a PHY profile.

DP_TYPE: This 3-bit field indicates the type of the DP. This is signaledaccording to the below table 13.

TABLE 13 Value DP Type 000 DP Type 1 001 DP Type 2 010~111 reserved

DP_GROUP_ID: This 8-bit field identifies the DP group with which thecurrent DP is associated. This can be used by a receiver to access theDPs of the service components associated with a particular service,which will have the same DP_GROUP_ID.

BASE_DP_ID: This 6-bit field indicates the DP carrying service signalingdata (such as PSI/SI) used in the Management layer. The DP indicated byBASE_DP_ID may be either a normal DP carrying the service signaling dataalong with the service data or a dedicated DP carrying only the servicesignaling data

DP_FEC_TYPE: This 2-bit field indicates the FEC type used by theassociated DP. The FEC type is signaled according to the below table 14.

TABLE 14 Value FEC_TYPE 00 16K LDPC 01 64K LDPC 10~11 Reserved

DP_COD: This 4-bit field indicates the code rate used by the associatedDP. The code rate is signaled according to the below table 15.

TABLE 15 Value Code rate 0000 5/15 0001 6/15 0010 7/15 0011 8/15 01009/15 0101 10/15  0110 11/15  0111 12/15  1000 13/15  1001~1111 Reserved

DP_MOD: This 4-bit field indicates the modulation used by the associatedDP. The modulation is signaled according to the below table 16.

TABLE 16 Value Modulation 0000 QPSK 0001 QAM-16 0010 NUQ-64 0011 NUQ-2560100 NUQ-1024 0101 NUC-16 0110 NUC-64 0111 NUC-256 1000 NUC-10241001~1111 reserved

DP_SSD_FLAG: This 1-bit field indicates whether the SSD mode is used inthe associated DP. If this field is set to value ‘1’, SSD is used. Ifthis field is set to value ‘0’, SSD is not used.

The following field appears only if PHY_PROFILE is equal to ‘010’, whichindicates the advanced profile:

DP_MIMO: This 3-bit field indicates which type of MIMO encoding processis applied to the associated DP. The type of MIMO encoding process issignaled according to the table 17.

TABLE 17 Value MIMO encoding 000 FR-SM 001 FRFD-SM 010~111 reserved

DP_TI_TYPE: This 1-bit field indicates the type of time-interleaving. Avalue of ‘0’ indicates that one TI group corresponds to one frame andcontains one or more TI-blocks. A value of ‘1’ indicates that one TIgroup is carried in more than one frame and contains only one TI-block.

DP_TI_LENGTH: The use of this 2-bit field (the allowed values are only1, 2, 4, 8) is determined by the values set within the DP_TI_TYPE fieldas follows:

If the DP_TI_TYPE is set to the value ‘1’, this field indicates PI, thenumber of the frames to which each TI group is mapped, and there is oneTI-block per TI group (NTI=1). The allowed PI values with 2-bit fieldare defined in the below table 18.

If the DP_TI_TYPE is set to the value ‘0’, this field indicates thenumber of TI-blocks NTI per TI group, and there is one TI group perframe (PI=1). The allowed PI values with 2-bit field are defined in thebelow table 18.

TABLE 18 2-bit field PI NTI 00 1 1 01 2 2 10 4 3 11 8 4

DP_FRAME_INTERVAL: This 2-bit field indicates the frame interval (IJUMP)within the frame-group for the associated DP and the allowed values are1, 2, 4, 8 (the corresponding 2-bit field is ‘00’, ‘01’, ‘10’, or ‘11’,respectively). For DPs that do not appear every frame of theframe-group, the value of this field is equal to the interval betweensuccessive frames. For example, if a DP appears on the frames 1, 5, 9,13, etc., this field is set to ‘4’. For DPs that appear in every frame,this field is set to ‘1’.

DP_TI_BYPASS: This 1-bit field determines the availability of timeinterleaver 5050. If time interleaving is not used for a DP, it is setto ‘1’. Whereas if time interleaving is used it is set to ‘0’.

DP_FIRST_FRAME_IDX: This 5-bit field indicates the index of the firstframe of the super-frame in which the current DP occurs. The value ofDP_FIRST_FRAME_IDX ranges from 0 to 31

DP_NUM_BLOCK_MAX: This 10-bit field indicates the maximum value ofDP_NUM_BLOCKS for this DP. The value of this field has the same range asDP_NUM_BLOCKS.

DP_PAYLOAD_TYPE: This 2-bit field indicates the type of the payload datacarried by the given DP. DP_PAYLOAD_TYPE is signaled according to thebelow table 19.

TABLE 19 Value Payload Type 00 TS. 01 IP 10 GS 11 reserved

DP_INBAND_MODE: This 2-bit field indicates whether the current DPcarries in-band signaling information. The in-band signaling type issignaled according to the below table 20.

TABLE 20 Value In-band mode 00 In-band signaling is not carried. 01INBAND-PLS is carried only 10 INBAND-ISSY is carried only 11 INBAND-PLSand INBAND-ISSY are carried

DP_PROTOCOL_TYPE: This 2-bit field indicates the protocol type of thepayload carried by the given DP. It is signaled according to the belowtable 21 when input payload types are selected.

TABLE 21 If If If DP_PAYLOAD_TYPE DP_PAYLOAD_TYPE DP_PAYLOAD_TYPE ValueIs TS Is IP Is GS 00 MPEG2-TS IPv4 (Note) 01 Reserved IPv6 Reserved 10Reserved Reserved Reserved 11 Reserved Reserved Reserved

DP_CRC_MODE: This 2-bit field indicates whether CRC encoding is used inthe Input Formatting block. The CRC mode is signaled according to thebelow table 22.

TABLE 22 Value CRC mode 00 Not used 01 CRC-8 10 CRC-16 11 CRC-32

DNP_MODE: This 2-bit field indicates the null-packet deletion mode usedby the associated DP when DP_PAYLOAD_TYPE is set to TS (‘00’). DNP_MODEis signaled according to the below table 23. If DP_PAYLOAD_TYPE is notTS (‘00’), DNP_MODE is set to the value ‘00’.

TABLE 23 Value Null-packet deletion mode 00 Not used 01 DNP-NORMAL 10DNP-OFFSET 11 reserved

ISSY_MODE: This 2-bit field indicates the ISSY mode used by theassociated DP when DP_PAYLOAD_TYPE is set to TS (‘00’). The ISSY_MODE issignaled according to the below table 24 If DP_PAYLOAD_TYPE is not TS(‘00’), ISSY_MODE is set to the value ‘00’.

TABLE 24 Value ISSY mode 00 Not used 01 ISSY-UP 10 ISSY-BBF 11 reserved

HC_MODE_TS: This 2-bit field indicates the TS header compression modeused by the associated DP when DP_PAYLOAD_TYPE is set to TS (‘00’). TheHC_MODE_TS is signaled according to the below table 25.

TABLE 25 Value Header compression mode 00 HC_MODE_TS 1 01 HC_MODE_TS 210 HC_MODE_TS 3 11 HC_MODE_TS 4

HC_MODE_IP: This 2-bit field indicates the IP header compression modewhen DP_PAYLOAD_TYPE is set to IP (‘01’). The HC_MODE_IP is signaledaccording to the below table 26.

TABLE 26 Value Header compression mode 00 No compression 01 HC_MODE_IP 110~11 reserved

PID: This 13-bit field indicates the PID number for TS headercompression when DP_PAYLOAD_TYPE is set to TS (‘00’) and HC_MODE_TS isset to ‘01’ or ‘10’.

RESERVED: This 8-bit field is reserved for future use.

The following field appears only if FIC_FLAG is equal to ‘1’:

FIC_VERSION: This 8-bit field indicates the version number of the FIC.

FIC_LENGTH_BYTE: This 13-bit field indicates the length, in bytes, ofthe FIC.

RESERVED: This 8-bit field is reserved for future use.

The following field appears only if AUX_FLAG is equal to ‘1’:

NUM_AUX: This 4-bit field indicates the number of auxiliary streams.Zero means no auxiliary streams are used.

AUX_CONFIG_RFU: This 8-bit field is reserved for future use.

AUX_STREAM_TYPE: This 4-bit is reserved for future use for indicatingthe type of the current auxiliary stream.

AUX_PRIVATE_CONFIG: This 28-bit field is reserved for future use forsignaling auxiliary streams.

FIG. 15 illustrates PLS2 data according to another embodiment of thepresent invention.

FIG. 15 illustrates PLS2-DYN data of the PLS2 data. The values of thePLS2-DYN data may change during the duration of one frame-group, whilethe size of fields remains constant.

The details of fields of the PLS2-DYN data are as follows:

FRAME_INDEX: This 5-bit field indicates the frame index of the currentframe within the super-frame. The index of the first frame of thesuper-frame is set to ‘0’.

PLS_CHANGE_COUNTER: This 4-bit field indicates the number ofsuper-frames ahead where the configuration will change. The nextsuper-frame with changes in the configuration is indicated by the valuesignaled within this field. If this field is set to the value ‘0000’, itmeans that no scheduled change is foreseen: e.g., value ‘1’ indicatesthat there is a change in the next super-frame.

FIC_CHANGE_COUNTER: This 4-bit field indicates the number ofsuper-frames ahead where the configuration (i.e., the contents of theFIC) will change. The next super-frame with changes in the configurationis indicated by the value signaled within this field. If this field isset to the value ‘0000’, it means that no scheduled change is foreseen:e.g. value ‘0001’ indicates that there is a change in the nextsuper-frame.

RESERVED: This 16-bit field is reserved for future use.

The following fields appear in the loop over NUM_DP, which describe theparameters associated with the DP carried in the current frame.

DP_ID: This 6-bit field indicates uniquely the DP within a PHY profile.

DP_START: This 15-bit (or 13-bit) field indicates the start position ofthe first of the DPs using the DPU addressing scheme. The DP_START fieldhas differing length according to the PHY profile and FFT size as shownin the below table 27.

TABLE 27 DP_START field size PHY profile 64K 16K Base 13 bits 15 bitsHandheld — 13 bits Advanced 13 bits 15 bits

DP_NUM_BLOCK: This 10-bit field indicates the number of FEC blocks inthe current TI group for the current DP. The value of DP_NUM_BLOCKranges from 0 to 1023

RESERVED: This 8-bit field is reserved for future use.

The following fields indicate the FIC parameters associated with theEAC.

EAC_FLAG: This 1-bit field indicates the existence of the EAC in thecurrent frame. This bit is the same value as the EAC_FLAG in thepreamble.

EAS_WAKE_UP_VERSION_NUM: This 8-bit field indicates the version numberof a wake-up indication.

If the EAC_FLAG field is equal to ‘1’, the following 12 bits areallocated for EAC_LENGTH_BYTE field. If the EAC_FLAG field is equal to‘0’, the following 12 bits are allocated for EAC_COUNTER.

EAC_LENGTH_BYTE: This 12-bit field indicates the length, in byte, of theEAC.

EAC_COUNTER: This 12-bit field indicates the number of the frames beforethe frame where the EAC arrives.

The following field appears only if the AUX_FLAG field is equal to ‘1’:

AUX_PRIVATE_DYN: This 48-bit field is reserved for future use forsignaling auxiliary streams. The meaning of this field depends on thevalue of AUX_STREAM_TYPE in the configurable PLS2-STAT.

CRC_32: A 32-bit error detection code, which is applied to the entirePLS2.

FIG. 16 illustrates a logical structure of a frame according to anembodiment of the present invention.

As above mentioned, the PLS, EAC, FIC, DPs, auxiliary streams and dummycells are mapped into the active carriers of the OFDM symbols in theframe. The PLS1 and PLS2 are first mapped into one or more FSS(s). Afterthat, EAC cells, if any, are mapped immediately following the PLS field,followed next by FIC cells, if any. The DPs are mapped next after thePLS or EAC, FIC, if any. Type 1 DPs follows first, and Type 2 DPs next.The details of a type of the DP will be described later. In some case,DPs may carry some special data for EAS or service signaling data. Theauxiliary stream or streams, if any, follow the DPs, which in turn arefollowed by dummy cells. Mapping them all together in the abovementioned order, i.e. PLS, EAC, FIC, DPs, auxiliary streams and dummydata cells exactly fill the cell capacity in the frame.

FIG. 17 illustrates PLS mapping according to an embodiment of thepresent invention.

PLS cells are mapped to the active carriers of FSS(s). Depending on thenumber of cells occupied by PLS, one or more symbols are designated asFSS(s), and the number of FSS(s) NFSS is signaled by NUM_FSS in PLS1.The FSS is a special symbol for carrying PLS cells. Since robustness andlatency are critical issues in the PLS, the FSS(s) has higher density ofpilots allowing fast synchronization and frequency-only interpolationwithin the FSS.

PLS cells are mapped to active carriers of the NFSS FSS(s) in a top-downmanner as shown in an example in FIG. 17. The PLS1 cells are mappedfirst from the first cell of the first FSS in an increasing order of thecell index. The PLS2 cells follow immediately after the last cell of thePLS1 and mapping continues downward until the last cell index of thefirst FSS. If the total number of required PLS cells exceeds the numberof active carriers of one FSS, mapping proceeds to the next FSS andcontinues in exactly the same manner as the first FSS.

After PLS mapping is completed, DPs are carried next. If EAC, FIC orboth are present in the current frame, they are placed between PLS and“normal” DPs.

FIG. 18 illustrates EAC mapping according to an embodiment of thepresent invention.

EAC is a dedicated channel for carrying EAS messages and links to theDPs for EAS. EAS support is provided but EAC itself may or may not bepresent in every frame. EAC, if any, is mapped immediately after thePLS2 cells. EAC is not preceded by any of the FIC, DPs, auxiliarystreams or dummy cells other than the PLS cells. The procedure ofmapping the EAC cells is exactly the same as that of the PLS.

The EAC cells are mapped from the next cell of the PLS2 in increasingorder of the cell index as shown in the example in FIG. 18. Depending onthe EAS message size, EAC cells may occupy a few symbols, as shown inFIG. 18.

EAC cells follow immediately after the last cell of the PLS2, andmapping continues downward until the last cell index of the last FSS. Ifthe total number of required EAC cells exceeds the number of remainingactive carriers of the last FSS mapping proceeds to the next symbol andcontinues in exactly the same manner as FSS(s). The next symbol formapping in this case is the normal data symbol, which has more activecarriers than a FSS.

After EAC mapping is completed, the FIC is carried next, if any exists.If FIC is not transmitted (as signaled in the PLS2 field), DPs followimmediately after the last cell of the EAC.

FIG. 19 illustrates FIC mapping according to an embodiment of thepresent invention.

shows an example mapping of FIC cell without EAC and (b) shows anexample mapping of FIC cell with EAC.

FIC is a dedicated channel for carrying cross-layer information toenable fast service acquisition and channel scanning. This informationprimarily includes channel binding information between DPs and theservices of each broadcaster. For fast scan, a receiver can decode FICand obtain information such as broadcaster ID, number of services, andBASE_DP_ID. For fast service acquisition, in addition to FIC, base DPcan be decoded using BASE_DP_ID. Other than the content it carries, abase DP is encoded and mapped to a frame in exactly the same way as anormal DP. Therefore, no additional description is required for a baseDP. The FIC data is generated and consumed in the Management Layer. Thecontent of FIC data is as described in the Management Layerspecification.

The FIC data is optional and the use of FIC is signaled by the FIC_FLAGparameter in the static part of the PLS2. If FIC is used, FIC_FLAG isset to ‘1’ and the signaling field for FIC is defined in the static partof PLS2. Signaled in this field are FIC_VERSION, and FIC_LENGTH_BYTE.FIC uses the same modulation, coding and time interleaving parameters asPLS2. FIC shares the same signaling parameters such as PLS2_MOD andPLS2_FEC. FIC data, if any, is mapped immediately after PLS2 or EAC ifany. FIC is not preceded by any normal DPs, auxiliary streams or dummycells. The method of mapping FIC cells is exactly the same as that ofEAC which is again the same as PLS.

Without EAC after PLS, FIC cells are mapped from the next cell of thePLS2 in an increasing order of the cell index as shown in an example in(a). Depending on the FIC data size, FIC cells may be mapped over a fewsymbols, as shown in (b).

FIC cells follow immediately after the last cell of the PLS2, andmapping continues downward until the last cell index of the last FSS. Ifthe total number of required FIC cells exceeds the number of remainingactive carriers of the last FSS, mapping proceeds to the next symbol andcontinues in exactly the same manner as FSS(s). The next symbol formapping in this case is the normal data symbol which has more activecarriers than a FSS.

If EAS messages are transmitted in the current frame, EAC precedes FIC,and FIC cells are mapped from the next cell of the EAC in an increasingorder of the cell index as shown in (b).

After FIC mapping is completed, one or more DPs are mapped, followed byauxiliary streams, if any, and dummy cells.

FIG. 20 illustrates a type of DP according to an embodiment of thepresent invention.

shows type 1 DP and (b) shows type 2 DP.

After the preceding channels, i.e., PLS, EAC and FIC, are mapped, cellsof the DPs are mapped. A DP is categorized into one of two typesaccording to mapping method:

Type 1 DP: DP is mapped by TDM

Type 2 DP: DP is mapped by FDM

The type of DP is indicated by DP_TYPE field in the static part of PLS2.FIG. 20 illustrates the mapping orders of Type 1 DPs and Type 2 DPs.Type 1 DPs are first mapped in the increasing order of cell index, andthen after reaching the last cell index, the symbol index is increasedby one. Within the next symbol, the DP continues to be mapped in theincreasing order of cell index starting from p=0. With a number of DPsmapped together in one frame, each of the Type 1 DPs are grouped intime, similar to TDM multiplexing of DPs.

Type 2 DPs are first mapped in the increasing order of symbol index, andthen after reaching the last OFDM symbol of the frame, the cell indexincreases by one and the symbol index rolls back to the first availablesymbol and then increases from that symbol index. After mapping a numberof DPs together in one frame, each of the Type 2 DPs are grouped infrequency together, similar to FDM multiplexing of DPs.

Type 1 DPs and Type 2 DPs can coexist in a frame if needed with onerestriction; Type 1 DPs always precede Type 2 DPs. The total number ofOFDM cells carrying Type 1 and Type 2 DPs cannot exceed the total numberof OFDM cells available for transmission of DPs:

D _(DP1) +D _(DP2) ≦D _(DP)  [Math figure 2]

where DDP1 is the number of OFDM cells occupied by Type 1 DPs, DDP2 isthe number of cells occupied by Type 2 DPs. Since PLS, EAC, FIC are allmapped in the same way as Type 1 DP, they all follow “Type 1 mappingrule”. Hence, overall, Type 1 mapping always precedes Type 2 mapping.

FIG. 21 illustrates DP mapping according to an embodiment of the presentinvention.

shows an addressing of OFDM cells for mapping type 1 DPs and (b) showsan addressing of OFDM cells for mapping for type 2 DPs.

Addressing of OFDM cells for mapping Type 1 DPs (0, . . . , DDP1-1) isdefined for the active data cells of Type 1 DPs. The addressing schemedefines the order in which the cells from the TIs for each of the Type 1DPs are allocated to the active data cells. It is also used to signalthe locations of the DPs in the dynamic part of the PLS2.

Without EAC and FIC, address 0 refers to the cell immediately followingthe last cell carrying PLS in the last FSS. If EAC is transmitted andFIC is not in the corresponding frame, address 0 refers to the cellimmediately following the last cell carrying EAC. If FIC is transmittedin the corresponding frame, address 0 refers to the cell immediatelyfollowing the last cell carrying FIC. Address 0 for Type 1 DPs can becalculated considering two different cases as shown in (a). In theexample in (a), PLS, EAC and FIC are assumed to be all transmitted.Extension to the cases where either or both of EAC and FIC are omittedis straightforward. If there are remaining cells in the FSS aftermapping all the cells up to FIC as shown on the left side of (a).

Addressing of OFDM cells for mapping Type 2 DPs (0, . . . , DDP2-1) isdefined for the active data cells of Type 2 DPs. The addressing schemedefines the order in which the cells from the TIs for each of the Type 2DPs are allocated to the active data cells. It is also used to signalthe locations of the DPs in the dynamic part of the PLS2.

Three slightly different cases are possible as shown in (b). For thefirst case shown on the left side of (b), cells in the last FSS areavailable for Type 2 DP mapping. For the second case shown in themiddle, FIC occupies cells of a normal symbol, but the number of FICcells on that symbol is not larger than CFSS. The third case, shown onthe right side in (b), is the same as the second case except that thenumber of FIC cells mapped on that symbol exceeds CFSS.

The extension to the case where Type 1 DP(s) precede Type 2 DP(s) isstraightforward since PLS, EAC and FIC follow the same “Type 1 mappingrule” as the Type 1 DP(s).

A data pipe unit (DPU) is a basic unit for allocating data cells to a DPin a frame.

A DPU is defined as a signaling unit for locating DPs in a frame. A CellMapper 7010 may map the cells produced by the TIs for each of the DPs. ATime interleaver 5050 outputs a series of TI-blocks and each TI-blockcomprises a variable number of XFECBLOCKs which is in turn composed of aset of cells. The number of cells in an XFECBLOCK, Ncells, is dependenton the FECBLOCK size, Nldpc, and the number of transmitted bits perconstellation symbol. A DPU is defined as the greatest common divisor ofall possible values of the number of cells in a XFECBLOCK, Ncells,supported in a given PHY profile. The length of a DPU in cells isdefined as LDPU. Since each PHY profile supports different combinationsof FECBLOCK size and a different number of bits per constellationsymbol, LDPU is defined on a PHY profile basis.

FIG. 22 illustrates an FEC structure according to an embodiment of thepresent invention.

FIG. 22 illustrates an FEC structure according to an embodiment of thepresent invention before bit interleaving. As above mentioned, Data FECencoder may perform the FEC encoding on the input BBF to generateFECBLOCK procedure using outer coding (BCH), and inner coding (LDPC).The illustrated FEC structure corresponds to the FECBLOCK. Also, theFECBLOCK and the FEC structure have same value corresponding to a lengthof LDPC codeword.

The BCH encoding is applied to each BBF (Kbch bits), and then LDPCencoding is applied to BCH-encoded BBF (Kldpc bits=Nbch bits) asillustrated in FIG. 22.

The value of Nldpc is either 64800 bits (long FECBLOCK) or 16200 bits(short FECBLOCK).

The below table 28 and table 29 show FEC encoding parameters for a longFECBLOCK and a short FECBLOCK, respectively.

TABLE 28 BCH error LDPC correction Rate Nldpc Kldpc Kbch capability Nbch− Kbch 5/15 64800 21600 21408 12 192 6/15 25920 25728 7/15 30240 300488/15 34560 34368 9/15 38880 38688 10/15  43200 43008 11/15  47520 4732812/15  51840 51648 13/15  56160 55968

TABLE 29 BCH error LDPC correction Rate Nldpc Kldpc Kbch capability Nbch− Kbch 5/15 16200 5400 5232 12 168 6/15 6480 6312 7/15 7560 7392 8/158640 8472 9/15 9720 9552 10/15  10800 10632 11/15  11880 11712 12/15 12960 12792 13/15  14040 13872

The details of operations of the BCH encoding and LDPC encoding are asfollows:

A 12-error correcting BCH code is used for outer encoding of the BBF.The BCH generator polynomial for short FECBLOCK and long FECBLOCK areobtained by multiplying together all polynomials.

LDPC code is used to encode the output of the outer BCH encoding. Togenerate a completed Bldpc (FECBLOCK), Pldpc (parity bits) is encodedsystematically from each Ildpc (BCH-encoded BBF), and appended to Ildpc.The completed Bldpc (FECBLOCK) are expressed as follow Math figure.

B _(ldpc) =[I _(ldpc) P _(ldpc) ]=[i ₀ ,i ₁ , . . . ,i _(K) _(ldpc) ₋₁,p ₀ ,p ₁ , . . . ,p _(N) _(ldpc) _(-K) _(ldpc) ₋₁]  [Math figure 3]

The parameters for long FECBLOCK and short FECBLOCK are given in theabove table 28 and 29, respectively.

The detailed procedure to calculate Nldpc

Kldpc parity bits for long FECBLOCK, is as follows:

1) Initialize the parity bits,

p ₀ =p ₁ =p ₂ = . . . =p _(N) _(ldpc) _(-K) _(ldpc) ₋₁=0  [Math figure4]

2) Accumulate the first information bit—i0, at parity bit addressesspecified in the first row of an addresses of parity check matrix. Thedetails of addresses of parity check matrix will be described later. Forexample, for rate 13/15:

p ₉₈₃ =p ₉₈₃ ⊕i ₀ p ₂₈₁₅ =p ₂₈₁₅ ⊕i ₀

p ₄₈₃₇ =p ₄₈₃₇ ⊕i ₀ p ₄₉₈₉ =p ₄₉₈₉ ⊕i ₀

p ₆₁₃₈ =p ₆₁₃₈ ⊕i ₀ p ₆₄₅₈ =p ₆₄₅₈ ⊕i ₀

p ₆₉₂₁ =p ₆₉₂₁ ⊕i ₀ p ₆₉₇₄ =p ₆₉₇₄ ⊕i ₀

p ₇₅₇₂ =p ₇₅₇₂ ⊕i ₀ p ₈₂₆₀ =p ₈₂₆₀ ⊕i ₀

p ₈₄₉₆ =p ₈₄₉₆ ⊕i ₀  [Math figure 5]

3) For the next 359 information bits, is, s=1, 2, . . . , 359 accumulateis at parity bit addresses using following Math figure.

{x+(s mod 360)×Q _(ldpc)} mod(N _(ldpc) −K _(ldpc))  [Math figure 6]

where x denotes the address of the parity bit accumulator correspondingto the first bit i0, and Qldpc is a code rate dependent constantspecified in the addresses of parity check matrix. Continuing with theexample, Qldpc=24 for rate 13/15, so for information bit i1, thefollowing operations are performed:

p ₈₄₉₆ =p ₁₀₀₇ ⊕i ₁ p ₂₈₃₉ =p ₂₈₃₉ ⊕i ₁

p ₄₈₆₁ =p ₄₈₆₁ ⊕i ₁ p ₅₀₁₃ =p ₅₀₁₃ ⊕i ₁

p ₆₁₆₂ =p ₆₁₆₂ ⊕i ₁ p ₆₄₈₂ =p ₆₄₈₂ ⊕i ₁

p ₆₉₄₅ =p ₆₉₄₅ ⊕i ₁ p ₆₉₉₈ =p ₆₉₉₈ ⊕i ₁

p ₇₅₉₆ =p ₇₅₉₆ ⊕i ₁ p ₈₂₈₄ =p ₈₂₈₄ ⊕i ₁

p ₈₅₂₀ =p ₈₅₂₀ ⊕i ₁  [Math figure 7]

4) For the 361st information bit i360, the addresses of the parity bitaccumulators are given in the second row of the addresses of paritycheck matrix. In a similar manner the addresses of the parity bitaccumulators for the following 359 information bits is, s=361, 362, . .. , 719 are obtained using the Math FIG. 6, where x denotes the addressof the parity bit accumulator corresponding to the information bit i360,i.e., the entries in the second row of the addresses of parity checkmatrix.

5) In a similar manner, for every group of 360 new information bits, anew row from addresses of parity check matrixes used to find theaddresses of the parity bit accumulators.

After all of the information bits are exhausted, the final parity bitsare obtained as follows:

6) Sequentially perform the following operations starting with i=1

p _(i) p _(i) ⊕p _(i-1) , i=1,2, . . . , N _(ldpc) −K _(ldpc)−1  [Mathfigure 8]

where final content of pi, i=0, 1, . . . Nldpc−Kldpc−1 is equal to theparity bit pi.

TABLE 30 Code Rate Qldpc 5/15 120 6/15 108 7/15 96 8/15 84 9/15 7210/15  60 11/15  48 12/15  36 13/15  24

This LDPC encoding procedure for a short FECBLOCK is in accordance witht LDPC encoding procedure for the long FECBLOCK, except replacing thetable 30 with table 31, and replacing the addresses of parity checkmatrix for the long FECBLOCK with the addresses of parity check matrixfor the short FECBLOCK.

TABLE 31 Code Rate Qldpc 5/15 30 6/15 27 7/15 24 8/15 21 9/15 18 10/15 15 11/15  12 12/15  9 13/15  6

FIG. 23 illustrates a bit interleaving according to an embodiment of thepresent invention.

The outputs of the LDPC encoder are bit-interleaved, which consists ofparity interleaving followed by Quasi-Cyclic Block (QCB) interleavingand inner-group interleaving.

shows Quasi-Cyclic Block (QCB) interleaving and (b) shows inner-groupinterleaving.

The FECBLOCK may be parity interleaved. At the output of the parityinterleaving, the LDPC codeword consists of 180 adjacent QC blocks in along FECBLOCK and 45 adjacent QC blocks in a short FECBLOCK. Each QCblock in either a long or short FECBLOCK consists of 360 bits. Theparity interleaved LDPC codeword is interleaved by QCB interleaving. Theunit of QCB interleaving is a QC block. The QC blocks at the output ofparity interleaving are permutated by QCB interleaving as illustrated inFIG. 23, where Ncells=64800/η mod or 16200/η mod according to theFECBLOCK length. The QCB interleaving pattern is unique to eachcombination of modulation type and LDPC code rate.

After QCB interleaving, inner-group interleaving is performed accordingto modulation type and order (η mod) which is defined in the below table32. The number of QC blocks for one inner-group, NQCB_IG, is alsodefined.

TABLE 32 Modulation type ηmod NQCB_IG QAM-16 4 2 NUC-16 4 4 NUQ-64 6 3NUC-64 6 6 NUQ-256 8 4 NUC-256 8 8 NUQ-1024 10 5 NUC-1024 10 10

The inner-group interleaving process is performed with NQCB_IG QC blocksof the QCB interleaving output. Inner-group interleaving has a processof writing and reading the bits of the inner-group using 360 columns andNQCB_IG rows. In the write operation, the bits from the QCB interleavingoutput are written row-wise. The read operation is performed column-wiseto read out m bits from each row, where m is equal to 1 for NUC and 2for NUQ.

FIG. 24 illustrates a cell-word demultiplexing according to anembodiment of the present invention.

shows a cell-word demultiplexing for 8 and 12 bpcu MIMO and (b) shows acell-word demultiplexing for 10 bpcu MIMO.

Each cell word (c0,1, c1,1, . . . , cη mod−1,1) of the bit interleavingoutput is demultiplexed into (d1,0,m, d1,1,m . . . , d1,η mod−1,m) and(d2,0,m, d2,1,m . . . , d2,η mod−1,m) as shown in (a), which describesthe cell-word demultiplexing process for one XFECBLOCK.

For the 10 bpcu MIMO case using different types of NUQ for MIMOencoding, the Bit Interleaver for NUQ-1024 is re-used. Each cell word(c0,1, c1,1, . . . , c9,1) of the Bit Interleaver output isdemultiplexed into (d1,0,m, d1,1,m . . . , d1,3,m) and (d2,0,m, d2,1,m .. . , d2,5 m), as shown in (b).

FIG. 25 illustrates a time interleaving according to an embodiment ofthe present invention.

to (c) show examples of TI mode.

The time interleaver operates at the DP level. The parameters of timeinterleaving (TI) may be set differently for each DP.

The following parameters, which appear in part of the PLS2-STAT data,configure the TI:

DP_TI_TYPE (allowed values: 0 or 1): Represents the TI mode; ‘0’indicates the mode with multiple TI blocks (more than one TI block) perTI group. In this case, one TI group is directly mapped to one frame (nointer-frame interleaving). ‘1’ indicates the mode with only one TI blockper TI group. In this case, the TI block may be spread over more thanone frame (inter-frame interleaving).

DP_TI_LENGTH: If DP_TI_TYPE=‘0’, this parameter is the number of TIblocks NTI per TI group. For DP_TI_TYPE=‘1’, this parameter is thenumber of frames PI spread from one TI group.

DP_NUM_BLOCK_MAX (allowed values: 0 to 1023): Represents the maximumnumber of XFECBLOCKs per TI group.

DP_FRAME_INTERVAL (allowed values: 1, 2, 4, 8): Represents the number ofthe frames IJUMP between two successive frames carrying the same DP of agiven PHY profile.

DP_TI_BYPASS (allowed values: 0 or 1): If time interleaving is not usedfor a DP, this parameter is set to ‘1’. It is set to ‘0’ if timeinterleaving is used.

Additionally, the parameter DP_NUM_BLOCK from the PLS2-DYN data is usedto represent the number of XFECBLOCKs carried by one TI group of the DP.

When time interleaving is not used for a DP, the following TI group,time interleaving operation, and TI mode are not considered. However,the Delay Compensation block for the dynamic configuration informationfrom the scheduler will still be required. In each DP, the XFECBLOCKsreceived from the SSD/MIMO encoding are grouped into TI groups. That is,each TI group is a set of an integer number of XFECBLOCKs and willcontain a dynamically variable number of XFECBLOCKs. The number ofXFECBLOCKs in the TI group of index n is denoted by NxBLOCK_Group(n) andis signaled as DP_NUM_BLOCK in the PLS2-DYN data. Note thatNxBLOCK_Group(n) may vary from the minimum value of 0 to the maximumvalue NxBLOCK_Group MAX (corresponding to DP_NUM_BLOCK_MAX) of which thelargest value is 1023.

Each TI group is either mapped directly onto one frame or spread over PIframes. Each TI group is also divided into more than one TI blocks(NTI), where each TI block corresponds to one usage of time interleavermemory. The TI blocks within the TI group may contain slightly differentnumbers of XFECBLOCKs. If the TI group is divided into multiple TIblocks, it is directly mapped to only one frame. There are three optionsfor time interleaving (except the extra option of skipping the timeinterleaving) as shown in the below table 33.

TABLE 33 Modes Descriptions Option-1 Each TI group contains one TI blockand is mapped directly to one frame as shown in (a). This option issignaled in the PLS2-STAT by DP_TI_TYPE = ‘0’ and DP_TI_LENGTH = ‘1’(NTI= 1). Option-2 Each TI group contains one TI block and is mapped to morethan one frame. (b) shows an example, where one TI group is mapped totwo frames, i.e., DP_TI_LENGTH = ‘2’ (PI = 2) and DP_FRAME_INTERVAL(IJUMP = 2). This provides greater time diversity for low data-rateservices. This option is signaled in the PLS2-STAT by DP_TI_TYPE = ‘1’.Option-3 Each TI group is divided into multiple TI blocks and is mappeddirectly to one frame as shown in (c). Each TI block may use full TImemory, so as to provide the maximum bit-rate for a DP. This option issignaled in the PLS2-STAT signaling by DP_TI_TYPE = ‘0’ and DP_TI_LENGTH= NTI, while PI = 1.

In each DP, the TI memory stores the input XFECBLOCKs (output XFECBLOCKsfrom the SSD/MIMO encoding block). Assume that input XFECBLOCKs aredefined as

$\begin{pmatrix}{d_{n,s,0,0},d_{n,s,0,1},\ldots \;,d_{n,s,0,{N_{cells} - 1}},d_{n,s,1,0},\ldots \;,d_{n,s,1,{N_{cells} - 1}}, \ldots \;,} \\{d_{n,s,{{N_{xBLOCK\_ TI}{({n,s})}} - 1},0},\ldots \;,d_{n,s,{{N_{xBLOCK\_ TI}{({n,s})}} - 1},{N_{cells} - 1}}}\end{pmatrix},$

where d_(n,s,r,q) is the qth cell of the rth XFECBLOCK in the sth TIblock of the nth TI group and represents the outputs of SSD and MIMOencodings as follows

$d_{n,s,r,q} = \left\{ {\begin{matrix}{f_{n,s,r,q},} & {{the}\mspace{14mu} {output}\mspace{14mu} {of}\mspace{14mu} {SSD}\mspace{14mu} \cdots \mspace{14mu} {encoding}} \\{g_{n,s,r,q},} & {{the}\mspace{14mu} {output}\mspace{14mu} {of}\mspace{14mu} {MIMO}\mspace{14mu} {encoding}}\end{matrix}.} \right.$

In addition, assume that output XFECBLOCKs from the time interleaver5050 are defined as

(h_(n, s, 0), h_(n, s, 1), … , h_(n, s, i), … , h_(n, s, N_(xBLOCK_TI)(n, s) × N_(cells) − 1)),

where h_(n,s,i) is the ith output cell (for i=0, . . . , N_(xBLOCK) _(_)_(TI)(n,s)×N_(cells)−1) in the sth TI block of the nth TI group.

Typically, the time interleaver will also act as a buffer for DP dataprior to the process of frame building. This is achieved by means of twomemory banks for each DP. The first TI-block is written to the firstbank. The second TI-block is written to the second bank while the firstbank is being read from and so on.

The TI is a twisted row-column block interleaver. For the sth TI blockof the nth TI group, the number of rows N_(r) of a TI memory is equal tothe number of cells N_(cells), i.e., N_(r)=N_(cells) while the number ofcolumns N_(c) is equal to the number N_(xBLOCK) _(_) _(TI)(n,s).

FIG. 26 illustrates a basic operation of a twisted row-column blockinterleaver according to an exemplary embodiment of the presentinvention.

FIG. 26A illustrates a writing operation in a time interleaver and FIG.26B illustrates a reading operation in the time interleaver. Asillustrated in FIG. 26A, a first XFECBLOCK is written in a first columnof a time interleaving memory in a column direction and a secondXFECBLOCK is written in a next column, and such an operation iscontinued. In addition, in an interleaving array, a cell is read in adiagonal direction. As illustrated in FIG. 26B, while the diagonalreading is in progress from a first row (to a right side along the rowstarting from a leftmost column) to a last row, N_(r) cells are read. Indetail, when it is assumed that z_(n,s,i) (i=, . . . , N_(r)N_(c)) is atime interleaving memory cell position to be sequentially read, thereading operation in the interleaving array is executed by calculating arow index R_(n,s,i), a column index C_(n,s,i), and associated twistparameter T_(n,s,i) as shown in an equation given below.

$\begin{matrix}{{{GENERATE}\left( {R_{n,s,i},C_{n,s,i}} \right)} = \left\{ {{R_{n,s,i} = {{mod}\left( {i,N_{r}} \right)}},{T_{n,s,i} = {{mod}\left( {{S_{shift} \times R_{n,s,i}},N_{c}} \right)}},{C_{n,s,i} = {{mod}\left( {{T_{n,s,i} + \left\lfloor \frac{i}{N_{r}} \right\rfloor},N_{c}} \right)}}} \right\}} & \left\lbrack {{Equation}\mspace{14mu} 9} \right\rbrack\end{matrix}$

Where, S_(shift) is a common shift value for a diagonal reading processregardless of N_(xBLOCK IT)(n,s) and the shift value is decided byN_(xBLOCK TI MAX) given in PLS2-STAT as shown in an equation givenbelow.

$\begin{matrix}{{f{or}}\mspace{14mu} \left\{ {{\begin{matrix}\begin{matrix}{N_{x\; {BLOC}\; K\; \_ \; T\; I\; \_ \; M\; {AX}}^{\prime} =} \\{{N_{x\; {BLOC}\; K\; \_ \; T\; {I\_}\; M\; {AX}} + 1},}\end{matrix} & {{{if}\mspace{14mu} N_{{xBLOCK}\; \_ \; T\; I\; \_ \; M\; {AX}}{mod}\; 2} = 0} \\\begin{matrix}{N_{x\; {BLOC}\; K\mspace{14mu} T\; I\mspace{11mu} M\; {AX}}^{\prime} =} \\{N_{x\; {BLOC}\; K\mspace{14mu} T\; I\mspace{11mu} M\; {AX}},}\end{matrix} & {{{if}\mspace{14mu} N_{{xBLOCK}\mspace{11mu} T\; I\mspace{11mu} M\; {AX}}{mod}\; 2} = 1^{\prime}}\end{matrix}S_{shift}} = \frac{N_{x\; {BLOC}\; K\; \_ \; T\; I\; \_ \; M\; {AX}}^{\prime} - 1}{2}} \right.} & \left\lbrack {{Equation}\mspace{14mu} 10} \right\rbrack\end{matrix}$

Consequently, the cell position to be read is calculated by a coordinatez_(n,s,i)=N_(r)C_(n,s,i)+R_(n,s,i).

FIG. 27 illustrates an operation of a twisted row-column blockinterleaver according to another exemplary embodiment of the presentinvention.

In more detail, FIG. 27 illustrates an interleaving array in the timeinterleaving memory for respective time interleaving groups including avirtual XFECBLOCK when N_(xBLOCK) _(_) _(TI)(0,0)=3,N_(xBLOCK TI)(1,0)=6, and N_(xBLOCK TI)(2,0)=5.

A variable N_(xBLOCK TI)(n,s)=N_(r) will be equal to or smaller thanN′_(xBLOCK) _(_) _(TI) _(_) _(MAX). Accordingly, in order for a receiverto achieve single memory interleaving regardless of N_(xBLOCK) _(_)_(TI)(n,s), the size of the interleaving array for the twistedrow-column block interleaver is set to a size ofN_(i)×N_(c)=N_(cells)×N′_(xBLOCK) _(_) _(TI) _(_) _(MAX) by insertingthe virtual XFECBLOCK into the time interleaving memory and a readingprocess is achieved as shown in an equation given below.

[Equation 11] p = 0; for i = 0;i < N_(cells)N_(xBLOCK) _(—) _(TI)_(MAX)′;i = i + 1 {GENERATE(R_(n,s,i),C_(n,s,i)); V_(t) =N_(r)C_(n,s,j) + R_(n,s,j)  if V_(i) < N_(cells)N_(xBLOCK TI)(n,s)  {  Z_(n,s,p) = V_(i); p = p + 1;   } }

The number of the time interleaving groups is set to 3. An option of thetime interleaver is signaled in the PLS2-STAT by DP_TI_TYPE=‘0’,DP_FRAME_INTERVAL=‘1’, and DP_TI_LENGTH=‘1’, that is, NTI=1, IJUMP=1,and PI=1. The number of respective XFECBLOCKs per time interleavinggroup, of which Ncells=30 is signaled in PLS2-DYN data byNxBLOCK_TI(0,0)=3, NxBLOCK_TI(1,0)=6, and NxBLOCK_TI(2,0)=5 of therespective XFECBLOCKs. The maximum number of XFECBLOCKs is signaled inthe PLS2-STAT data by NxBLOCK_Group_MAX and this is continued to└N_(xBLOCK) _(_) _(Group) _(_) _(MAX)/N_(TI)┘=N_(xBLOCK) _(_) _(TI) _(_)_(MAX)=6.

FIG. 28 illustrates a diagonal reading pattern of the twisted row-columnblock interleaver according to the exemplary embodiment of the presentinvention.

In more detail, FIG. 28 illustrates a diagonal reading pattern fromrespective interleaving arrays having parameters N′_(xBLOCK TI MAX)=7and Sshift=(7−1)/2=3. In this case, during a reading process expressedby a pseudo code given above, when V_(i)≧N_(cells)N_(xBLOCK) _(_)_(TI)(n,s), a value of Vi is omitted and a next calculation value of Viis used.

FIG. 29 illustrates XFECBLOCK interleaved from each interleaving arrayaccording to an exemplary embodiment of the present invention.

FIG. 29 illustrates XFECBLOCK interleaved from each interleaving arrayhaving parameters N′_(xBLOCK) _(_) _(TI) _(_) _(MAX)=7 and Sshift=3according to an exemplary embodiment of the present invention.

FIG. 30 illustrates a synchronization and demodulation module accordingto an embodiment of the present invention.

The synchronization and demodulation module illustrated in FIG. 30corresponds to the embodiment of the synchronization and demodulationmodule described in FIG. 9. Further, the synchronization anddemodulation module illustrated in FIG. 30 may perform an inverseoperation of the waveform generation module described in FIG. 9.

As illustrated in FIG. 30, the synchronization and demodulation moduleaccording to the embodiment of the present invention as an embodiment ofa synchronization and demodulation module of a receiving apparatus usingm Rx antennas may include m processing blocks for demodulating andoutputting a signal input as long as m paths. All m processing blocksmay perform the same processing procedure. Hereinafter, an operation ofa first processing block 30000 among m processing blocks will beprimarily described.

The first processing block 30000 may include a tuner 30100, an ADC block30200, a preamble detector 30300, a guard sequence detector 30400, awaveform transform block 30500, a time/frequency synchronization block30600, a reference signal detector 30700, a channel equalizer 30800, andan inverse waveform transform block 30900.

The tuner 30100 selects a desired frequency band and compensates amagnitude of a received signal to output the signal to the ADC block30200.

The ADC block 30200 may transform the signal output from the tuner 30100to a digital signal.

The preamble detector 30300 may detect a preamble (alternatively, apreamble signal or a preamble symbol) in order to verify whether thedigital signal is a signal of a system corresponding to the receivingapparatus. In this case, the preamble detector 30300 may decode basictransmission parameters received through the preamble.

The guard sequence detector 30400 may detect a guard sequence in thedigital signal. The time frequency synchronization block 30600 mayperform time/frequency synchronization by using the detected guardsequence and the channel equalizer 30800 may estimate a channel througha sequence received/restored by using the detected guard sequence.

When inverse waveform transform is performed at a transmitting side, thewaveform transform block 30500 may perform an inverse transformprocedure to the inverse waveform transform. When a broadcasttransmitting/receiving system according to the embodiment of the presentinvention a multi-carrier system, the waveform transform block 30500 mayperform an FFT transform procedure. Further, in the case where thebroadcast transmitting/receiving system according to the embodiment ofthe present invention is a single carrier system, when received signalsin a time domain are used to be processed in a frequency domain or allof the received signals are processed in the time domain, the waveformtransform block 30500 may not be used.

The time/frequency synchronization block 30600 may receive output dataof the preamble detector 30300, the guard sequence detector 30400, andthe reference signal detector 30700 and perform time synchronization andcarrier frequency synchronization including guard sequence detection andblock window positioning for a detected signal. In this case, thetime/frequency synchronization block 30600 may feed back and use anoutput signal of the waveform transform block 30500 for frequencysynchronization.

The reference signal detector 30700 may detect a received referencesignal. Therefore, the receiving apparatus according to the embodimentof the present invention may perform synchronization or channelestimation.

The channel equalizer 30800 may estimate a transmission channel up toeach receiving apparatus from each transmitting antenna from the guardsequence or the reference signal and perform channel equalization foreach received data by using the estimated channel.

When the waveform transform block 30500 performs waveform transform inorder to efficiently perform the synchronization and channelestimation/equalization, the inverse waveform transform block 30900 mayserve to restore each received data to an original received data domainagain. In the case where the broadcast transmitting/receiving systemaccording to the embodiment of the present invention is the singlecarrier system, the waveform transform block 30500 may perform FFT inorder to perform the synchronization/channel estimation/equalization inthe frequency domain and the inverse waveform transform block 30900performs IFFT for a signal of which channel equalization is completed torestore a transmitted data symbol. When the broadcasttransmitting/receiving system according to the embodiment of the presentinvention is a multi-carrier system, the inverse waveform transformblock 30900 may not be used.

Further, the aforementioned blocks may be omitted according to anintention of a designer or substituted by other blocks having a similaror the same function.

FIG. 31 illustrates a frame parsing module according to an embodiment ofthe present invention.

The frame parsing module illustrated in FIG. 31 correspond to theembodiment of the frame parsing module described in FIG. 9.

As illustrated in FIG. 31, the frame parsing module according to theembodiment of the present invention may include at least one or moreblock deinterleavers 31000 and at least one or more cell demapper 31100.

The block deinterleaver 31000 may perform deinterleaving for data pereach signal block with respect to data input into respective data pathsof m receiving antennas and processed in the synchronization anddemodulation module. In this case, as described in FIG. 8, whenpair-wise interleaving is performed at the transmitting side, the blockdeinterleaver 31000 may process two consecutive data for each input pathas one pair. Therefore, the block deinterleaver 31000 may output twoconsecutive output data even when deinterleaving the data. Further, theblock deinterleaver 31000 performs an inverse procedure of theinterleaving procedure performed at the transmitting side to output thedata according to an original data sequence.

The cell demapper 31100 may extract cells corresponding to common datafrom a received signal frame, cells corresponding to a data pipe, andcells corresponding to PLS data. In case of need, the cell demapper31100 merges data distributed and transmitted to a plurality of parts tooutput the merged data as one stream. Further, as described in FIG. 7,when two consecutive cell input data are processed as one pair to bemapped, the cell demapper 31100 may perform the pair-wise cell demappingof processing two consecutive input cells as one unit as an inverseprocedure corresponding thereto.

Further, the cell demapper 31100 may extract and output all PLSsignaling data received through a current frame as PLS-pre and PLS-postdata, respectively.

The aforementioned blocks may be omitted according to an intention of adesigner or substituted by other blocks having a similar or the samefunction.

FIG. 32 illustrates a demapping and decoding module according to anembodiment of the present invention.

The demapping and decoding module illustrated in FIG. 32 corresponds tothe embodiment of the demapping and decoding module described in FIG. 9.

As described above, the coding and modulation module of the transmittingapparatus according to the embodiment of the present invention mayindependently apply and process SISO, MISO, and MIMO schemes to inputdata pipes for respective paths. Therefore, the demapping and decodingmodule illustrated in FIG. 32 may also include blocks for SISO, MISO,and MIMO-processing data output from a frame parser to correspond to thetransmitting apparatus, respectively.

As illustrated in FIG. 32, the demapping and decoding module accordingto the embodiment of the present invention may include a first block32000 for the SISO scheme, a second block 32100 for the MISO scheme, anda third block 32200 for the MIMO scheme, and a fourth block 32300processing PLS pre/post information. The demapping and decoding moduleillustrated in FIG. 32 is just an embodiment and the demapping anddecoding module may include only the first block 32000 and the fourthblock 32300, only the second block 32100 and the fourth block 32300, andonly the third block 32200 and the fourth block 32300 according to theintension of the designer. That is, the demapping and decoding modulemay include blocks for processing the respective data pipes similarly ordifferently according to the intention of the designer.

Hereinafter, each block will be described.

The first block 32000 as a block for SISO-processing the input data pipemay include a time de-interleaver block 32010, a cell de-interleaverblock 32020, a constellation demapper block 32030, a cell to bit muxblock 32040, a bit de-interleaver block 32050, and an FEC decoder block32060.

The time de-interleaver block 32010 may perform an inverse procedure ofa time interleaver block. That is, the time de-interleaver block 32010may deinterleave an input symbol interleaved in the time domain to anoriginal position.

The cell de-interleaver block 32020 may perform an inverse procedure ofa cell interleaver block. That is, the cell de-interleaver block 32020may deinterleave positions of cells spread in one FEC block to originalpositions.

The constellation demapper block 32030 may perform an inverse procedureof a constellation mapper block. That is, the constellation demapperblock 32030 may demap an input signal of a symbol domain to data of abit domain. Further, the constellation demapper block 32030 may outputbit data decided by performing a hard decision and output alog-likelihood ratio (LLR) of each bit corresponding to a soft decisionvalue or a probabilistic value. When the transmitting side applies arotated constellation in order to acquire an additional diversity gain,the constellation demapper block 32030 may perform 2-dimensional LLRdemapping corresponding to the rotated constellation. In this case, theconstellation demapper 32030 may perform a calculation so that thetransmitting apparatus compensates a delay value performed with respectto an I or Q component at the time of calculating the LLR.

The cell to bit mux block 32040 may perform an inverse procedure of abit to cell demux block. That is, the cell to bit mux block 32040 mayrestore bit data mapped in a bit to cell demux block to an original bitstream form.

The bit de-interleaver block 32050 may perform an inverse procedure of abit interleaver block. That is, the bit de-interleaver block 32050 maydeinterleave the bit stream output in the cell to bit mux block 32040according to an original sequence.

The FEC decoder block 32060 may perform an inverse procedure of an FECencoder block. That is, the FEC decoder block 32060 may correct an errorwhich occurs on a transmission channel by performing LDPC decoding andBCH decoding.

The second block 32100 as a block for MISO-processing the input datapipe may include the time de-interleaver block, the cell de-interleaverblock, the constellation demapper block, the cell to bit mux block, thebit de-interleaver block, and the FEC decoder block similarly to thefirst block 32000 as illustrated in FIG. 32, but the second block 32100is different from the first block 32000 in that the second block 32100further includes an MISO decoding block 32110. Since the second block32100 performs a procedure of the same role from the time deinterleaverup to the output similarly to the first block 32000, a description ofthe same blocks will be omitted.

The MISO decoding block 32110 may perform an inverse procedure of theMISO processing block. When the broadcast transmitting/receiving systemaccording to the embodiment of the present invention is a system usingSTBC, the MISO decoding block 32110 may perform Alamouti decoding.

The third block 32200 as a block for MIMO-processing the input data pipemay include the time de-interleaver block, the cell de-interleaverblock, the constellation demapper block, the cell to bit mux block, thebit de-interleaver block, and the FEC decoder block similarly to thesecond block 32100 as illustrated in FIG. 32, but the third block 32200is different from the second block 32100 in that the third block 32200further includes an MIMO decoding block 32210. Operations of the timede-interleaver, cell de-interleaver, constellation demapper, cell to bitmux, and bit de-interleaver blocks included in the third block 32200 maybe different from operations and detailed functions of the correspondingblocks included in the first and second blocks 32000 and 32100, but theblocks included in the third block 32200 are the same as the blocksincluded in the first and second blocks in terms of basic roles.

The MIMO decoding block 32210 may receive output data of the celldeinterleaver as an input with respect to m receiving antenna inputsignal and perform MIMO decoding as an inverse procedure of the MIMOprocessing block. The MIMO decoding block 32210 may perform maximumlikelihood decoding in order to perform maximum decoding performance orsphere decoding for reducing complexity. Alternatively, the MIMOdecoding block 32210 performs MMSE detection or perform iterativedecoding combinationally with the MMSE detection to secure improveddecoding performance.

The fourth block 32300 as a block for processing PLS pre/postinformation may perform SISO or MISO decoding. The fourth block 32300may perform an inverse procedure of the fourth block.

The operations of the time de-interleaver, cell de-interleaver,constellation demapper, cell to bit mux, and bit de-interleaver blocksincluded in the fourth block 32300 may be different from operations anddetailed functions of the corresponding blocks included in the first tothird blocks 32000 to 32200, but the blocks included in the fourth block32300 are the same as the blocks included in the first to third blocksin terms of basic roles.

A shortened/punctured FEC decoder 32310 may perform an inverse procedureof the shortened/punctured FEC encoder block. That is, theshortened/punctured FEC decoder 32310 may perform de-shortening andde-puncturing, and thereafter, FEC decoding data received while beingshortened/punctured according to the length of the PLS data. In thiscase, since the FEC decoder used in the data pipe may be similarly usedeven in the PLS, separate FEC decoder hardware for only the PLS is notrequired, and as a result, system design is easy and efficient coding isavailable.

The aforementioned blocks may be omitted according to an intention of adesigner or substituted by other blocks having a similar or the samefunction.

Consequently, as illustrated in FIG. 32, the demapping and decodingmodule according to the embodiment of the present invention may outputto the output processor the data pipe and the PLS information processedfor each path.

FIGS. 33 and 34 illustrate an output processor according to anembodiment of the present invention.

FIG. 33 illustrates an output processor according to an embodiment ofthe present invention.

The output processor illustrated in FIG. 33 corresponds to theembodiment of the output processor described in FIG. 9. Further, theoutput processor illustrated in FIG. 33 which is used to receive asingle data pipe output from the demapping and decoding module andoutput a single output stream may perform an inverse operation of theinput formatting module.

The output processor of FIG. 33 implements functions, processes, and/ormethods proposed in FIGS. 50, 51, and 53 to be described below.

The output processor illustrated in FIG. 33 may include a BB Descrambler33000, a padding removable block 33100, a CRC-8 decoder block 33200, anda BB frame processor block 33300.

The BB Descrambler block 33000 generates the same PRBS as used at thetransmitting side with respect to an input bit stream and XOR-operatesthe PRBS and the bit stream to perform descrambling.

The padding removable block 33100 may remove a padding bit inserted bythe transmitting side as necessary.

The CRC-8 decoder block 33200 perform CRC decoding of the bit streamreceived from the padding removable block 33100 to check a block error.

The BB frame processor block 33300 may decode information transmitted tothe BB frame header and restore an MP3G-TS, an IP stream (v4 or v6), ora generic stream.

The aforementioned blocks may be omitted according to the intention ofthe designer or substituted by other blocks having a similar or the samefunction.

FIG. 34 illustrates an output processor according to another embodimentof the present invention.

The output processor illustrated in FIG. 34 corresponds to theembodiment of the output processor described in FIG. 9. Further, theoutput processor illustrated in FIG. 34 corresponds to the case ofreceiving multiple data pipes output from the demapping and decodingmodule. Decoding the multiple data pipes may include the case of mergingcommon data which may be commonly applied to a plurality of data pipesand a data pipe associated with the common data and decoding the mergedcommon data and data pipe or the case in which the receiving apparatussimultaneously decodes several services or service components (includinga scalable video service).

The output processor illustrated in FIG. 34 may include the BBdescrambler block, the padding removable block, the CRC-8 decoder block,and the BB frame processor block 33300 similarly to the outputprocessor.

The output processor of FIG. 34 implements functions, processes, and/ormethods proposed in FIGS. 50, 51, and 53 to be described below.

The respective blocks may be different from the blocks described in FIG.33 in terms of the operations and the detailed operations, but therespective blocks are the same as the blocks of FIG. 33 in terms of thebasic role.

A de-jitter buffer block 34000 included in the output processorillustrated in FIG. 34 may compensate a delay arbitrarily inserted atthe transmitting side according to a restored time to output (TTO)parameter for synchronizing the multiple data pipes.

Further, a null packet insertion block 34100 may restore a null packetremoved in the stream by referring to restored deleted null packet (DNP)information and output the common data.

A TS clock regeneration block 34200 may restore detailed timesynchronization of an output packet based on ISCR-input stream timereference information.

A TS recombining block 34300 recombines the common data output from thenull packet insertion block 34100 and the data pipes associated with thecommon data to restore the recombined common data and data pipes to theoriginal MPEG-TS, IP stream (v4 or v6), or generic stream and output therestored MPEG-TS, IP stream (v4 or v6), or generic stream. The TTO, DNP,and ISCR information may be all acquired through the BB frame header.

An in-band signaling decoder block 34400 may restore and output in-bandphysical layer signaling information transmitted through a padding bitfield in each FEC frame of the data pipe.

The output processor illustrated in FIG. 34 performs BB descramblingPLS-pre information and PLS-post information input according to thePLS-pre path and the PLS-post path, respectively and decodes thedescrambled data to restore the original PLS data. The restored PLS datamay transferred to the system controller in the receiving apparatus andthe system controller may provide a required parameter to thesynchronization and demodulation module, the frame parsing module, thedemapping and decoding module, and the output processor module in thereceiving apparatus.

The aforementioned blocks may be omitted according to the intention ofthe designer or substituted by other blocks having a similar or the samefunction.

FIG. 35 illustrates a coding and modulation module according to anotherembodiment of the present invention.

The coding and modulation module illustrated in FIG. 35 may include afirst block 35000 for the SISO scheme, a second block 35100 for the MISOscheme, and a third block 35200 for the MIMO scheme, and a fourth block35300 for processing PLS pre/post information in order to control QoSfor each service or service component transmitted through each datapipe. Further, the coding and modulation module according to theembodiment of the present invention may include blocks for similarly ordifferently processing the respective data pipes according to theintention of the designer as described above. The first to fourth blocks35000 to 35300 illustrated in FIG. 35 may include substantially the sameblocks as the first to fourth blocks.

However, the first to fourth blocks 35000 to 35300 are different fromthe aforementioned first to fourth blocks in that a function of aconstellation mapper block 35010 included in the first to third blocks35000 to 35200 is different from that of the constellation mapper blockincluded in the first to third blocks, and a rotation and I/Ointerleaver block 35020 is included between the cell interleaver and thetime interleaver of the first to fourth blocks 35000 to 35300, and aconfiguration of the third block 35200 for the MIMO scheme is differentfrom that of the third block for the MIMO scheme.

The constellation demapper block 35010 illustrated in FIG. 35 may map aninput bit word to a complex symbol.

The constellation mapper block 35010 illustrated in FIG. 35 may becommonly applied to the first to third blocks 35000 to 35200 asdescribed above.

The rotation and I/O interleaver block 35020 independently interleavesin-phase and quadrature-phase components of respective complex symbolsof cell-interleaved data output from the cell interleaver to output theinterleaved components by the unit of the symbol. The number of inputdata and output symbols of the rotation and I/O interleaver block 35020is two or more and may be changed according to the intention of thedesigner. Further, the rotation and I/O interleaver block 35020 may notinterleave the in-phase components.

The rotation and I/O interleaver block 35020 may be commonly applied tothe first to fourth blocks 35000 to 35300 as described above. In thiscase, whether the rotation and I/O interleaver block 35020 is applied tothe fourth block 35300 for processing the PLS pre/post information maybe signaled through the aforementioned preamble.

The third block 35200 for the MIMO scheme may include a Q-blockinterleaver block 35210 and a complex symbol generator block 35220 asillustrated in FIG. 35.

The Q-block interleaver block 35210 may perform permutation of a paritypart of the FEC-encoded FEC block received from the FEC encoder.Therefore, a parity part of an LDPC H matrix may be made in a cyclicstructure similarly to an information part. The Q-block interleaverblock 35210 permutates sequences of bit blocks having a Q size in theLDPC H matrix and thereafter, performs row-column block interleaving ofthe bit blocks to generate and output a final bit stream.

The complex symbol generator block 35220 may receive the bit streamsoutput from the Q-block interleaver block 35210 and map the received bitstreams to the complex symbol and output the mapped bit streams andcomplex symbol. In this case, the complex symbol generator block 35220may output the symbols through at least two paths. This may be changedaccording to the intension of the designer.

The aforementioned blocks may be omitted according to the intention ofthe designer or substituted by other blocks having a similar or the samefunction.

Consequently, as illustrated in FIG. 35, the coding and modulationaccording to another embodiment of the present invention may output thedata pipe, the PLS-pre information, and the PLS-post informationprocessed for each path to a frame structure module.

FIG. 36 illustrates a demapping and decoding module according to anotherembodiment of the present invention.

The demapping and decoding module illustrated in FIG. 36 corresponds toanother embodiment of the demapping and decoding module described inFIGS. 9 and 32. Further, the demapping and decoding module illustratedin FIG. 36 may perform an inverse operation of the coding and modulationmodule described in FIG. 35.

As illustrated in FIG. 36, the demapping and decoding module accordingto another embodiment of the present invention may include a first block36000 for the SISO scheme, a second block 36100 for the MISO scheme, athird block 36200 for the MIMO scheme, and a fourth block 36300 forprocessing the PLS pre/post information. Further, the demapping anddecoding module according to the embodiment of the present invention mayinclude blocks for similarly or differently processing the respectivedata pipes according to the intention of the designer as describedabove. The first to fourth blocks 36000 to 36300 illustrated in FIG. 36may include substantially the same blocks as the first to fourth blocks32000 to 32300 described in FIG. 32.

However, the first to fourth blocks 36000 to 36300 are different fromthe aforementioned first to fourth blocks in that an I/Q deinterleaverand derotation block 36010 is included between the time deinterleaverand the cell deinterleaver, a function a constellation demapper block36020 included in the first to third blocks 36000 to 36200 is differentfrom the function of the constellation mapper 42030 included in thefirst to third blocks 32000 to 32200 of FIG. 32, and a configuration ofthe third block 36200 for the MIMO scheme is different from that of thethird block 36200 for the MIMO scheme illustrated in FIG. 36.Hereinafter, the same blocks as FIG. 36 will not described and theaforementioned differences will be primarily described.

The I/Q deinterleaver and derotation block 36010 may perform an inverseprocedure of the rotation and I/Q interleaver block 35020 described inFIG. 35. That is, the I/Q deinterleaver and derotation block 36010 maydeinterleave I and Q components I/Q interleaved and transmitted at thetransmitting side and derotate and output the complex symbol having therestored I/Q component again.

The I/Q deinterleaver and derotation block 36010 may be commonly appliedto the first to fourth blocks 36000 to 36300 as described above. In thiscase, whether the I/Q deinterleaver and derotation block 36010 isapplied to the fourth block 36300 for processing the PLS pre/postinformation is may be signaled through the aforementioned preamble.

The constellation demapper block 36020 may perform an inverse procedureof the constellation mapper block 35010 described in FIG. 35. That is,the constellation demapper block 36020 may not perform derotation, butdemap the cell-deinterleaved data.

The third block 36200 for the MIMO scheme may include a complex symbolgenerator block 36210 and a Q-block deinterleaver block 36220 asillustrated in FIG. 36.

The complex symbol parsing block 36210 may perform an inverse procedureof the complex symbol generator block 35220 described in FIG. 35. Thatis, the complex symbol parsing block 36210 may parse the complex datasymbol, and demap the parsed complex data symbol to the bit data andoutput the data. In this case, the complex symbol parsing block 36210may receive the complex data symbols through at least two paths.

The Q-block deinterleaver block 36220 may perform an inverse procedureof the Q-block interleaver block 35210 described in FIG. 35. That is,the Q-block deinterleaver block 36220 may restore the Q-size blocks bythe row-column deinterleaving, restore the permutated sequences of therespective blocks to the original sequences, and thereafter, restore thepositions of the parity bits to the original positions through theparity deinterleaving and output the parity bits.

The aforementioned blocks may be omitted according to the intention ofthe designer or substituted by other blocks having a similar or the samefunction.

Consequently, as illustrated in FIG. 36, the demapping and decodingmodule according to another embodiment of the present invention mayoutput the data pipe and the PLS information processed for each path tothe output processor.

Hereinafter, a new BBF header structure for reducing the overhead of theBBF transmission and adding various functions using the padding fieldproposed in the specification will be described in detail.

FIG. 37 illustrates one example of a mode adaptation module proposed inthe specification.

As described above, the input formatting module includes the modeadaptation module.

A configuration of the mode adaptation module of FIG. 37 may bepartially different from that of the mode adaptation module describedabove.

As illustrated in FIG. 37, the mode adaptation module may be configuredto include at least one of a pre processing or splitting block 3710, aninput interface block 3720, an input stream synchronizer block 3730, adelay compensating block 3740, a header compression block 3750, a nulldata reuse block 3760, a null packet detection block 3770, and a BBframe header insertion block 3780.

The pre processing block may split or demultiplex a plurality of inputstreams to a plurality of data pipes. Herein, the data pipe may bereferred to as a physical layer pipe (PLP). Herein, the input stream maybe a MPEG2-TS, an Internet protocol (IP), and/or the generic stream(GS).

In some embodiments, an input stream having a different form may also beavailable.

The header compression block may compress a packet header. This may usedto increase transmission efficiency of the TS or IP input stream. Sincethe receiver has had a priory information of the header, known data maybe removed at the transmitting side. For example, information such asthe PID, or the like may be compressed and information having differentforms may be removed or substituted. In some embodiments, the headercompression block may be positioned subsequent to the null packetdeletion block.

The null data reuse block may perform an operation of inserting nulldata into the packet after the header compression. This block may beomitted in some embodiments.

The BB frame header insertion block may operate in a different mode thanthe aforementioned BB frame header insertion block.

The specification provides a method for reducing signaling of a datafield length of the frame (Data field length signaling reductionmethod).

Further, the specification provides a method for reducing the overheadfor the transmission of the BB frame to the FEC block.

That is, a new BB frame configuration method proposed in thespecification may be performed in the BB frame header insertion block.

By the method proposed in the specification, the BB frame and the BBframe header may be configured. The specification may relate to aprocedure in which the BB frame is generated in order to transfer theinput stream to the FEC block through the input processing.

Further, the specification may relate to a method for increasing thetransmission efficiency by decreasing the size of the BB frame header.Detailed contents associated with the BB frame header insertion blockwill be described below.

In the related art, in the BB frame, a data field length (DFL) wasallocated to each BB frame header in order to notify the length of thedata field to the receiving apparatus. The DFL may be 16 bits or 11bits. As a result, the related art is large in overhead for the BBFtransmission.

When the data field length is changed in the BB frame having thecontinuously same size, the BB frame may not fully be filled with thedata or the BB frame may include in-band signaling information.

In another related art, the BB frame transmitted only an indicatorinstead of directly notifying the length of the data field. In addition,the BB frame signaled the length of a padding of the BB frame in thepadding. However, in this case, since the in-band signaling is notconsidered, when the in-band signaling is operated, there may be arestriction.

A method proposed in the specification may be a method for configuringthe BB frame header that can reduce the DFL and insert an additionalfield. Herein, the additional field may indicate a type of the in-bandsignaling, or the like or may be used for another purpose.

Through the method proposed in the specification, the overhead for theBBF transmission may be minimized and various functions may be added tothe padding (alternatively, stuffing) field.

FIG. 38 illustrates one example of an output processor proposed in thespecification.

As described above, the output processor may include the BB frame headerparser block. Components the output processor of FIG. 38 may bepartially different from those of the output processor described above.

The output processor of FIG. 38 implements functions, processes, and/ormethods proposed in FIGS. 50, 51, and 53 to be described below.

The output processor may be configured to include at least one of a BBframe header parser block 3810, a null packet insertion block 3820, anull data regenerator block 3830, a header decompression block 3840, aTS clock regeneration block 3850, a de-jitter buffer block 3860, and aTS recombining block 3870.

Herein, the null packet insertion block, the TS clock regenerationblock, the de-jitter buffer bloc, and the TS recombining block mayperform the same operations as the blocks of the output processor.

The BB frame header configuring method proposed in the specification maycorrespond to the BB frame header parser block at the receiving side(alternatively, the receiving apparatus or the receiver).

The BB frame header parser block 3810 may operate differently from theBB frame header parser block. The BB frame header parser block 3810 mayperform an operation of parsing the BB frame header according to themethod proposed in the specification.

The BB frame and the BB frame header configuring method proposed in thespecification will be described below.

The null data regeneration block may correspond to the null data reuseblock at the receiving side. The null data regeneration block may outputan output to the heard decompression block. This block may be omitted insome embodiments.

The header decompression block may correspond to the header compressionblock at the receiving side. The header decompression block may restorethe compression of the compressed packet header. As described above, thepacket header may be compressed to increase the transmission efficiencyof the TS or IP input stream. In some embodiments, the headerdecompression block may be positioned ahead of the null packet insertionblock.

FIG. 39 illustrates one example of a BB frame structure in the relatedart.

Data streams input into the input formatting module, in particular, themode adaptation module may be sliced with an appropriate length so thatthe BICM module may perform FEC. Therefore, the BB frame may begenerated.

The length of the data field of the BB frame corresponds to a valueacquired by subtracting the length of the BB frame header from the totallength of the BB frame.

An actual user packet (UP) may be inserted into a data field part of theBBF.

The length of the data field may be notified in the data field length(DFL) field of the BB frame header. The DFL field may be expressed asDFL.

The BB frame generated through input formatting may be encoded in apredetermined FEC block.

Herein, the total length of the BB frame may be fixed.

Further, when the length of the data field of the BBF is changed, the BBframe may be not fully filled with the UP because the UP is notsufficient or the in-band signaling information may be intentionallyincluded.

When the BB frame may be not fully filled, the corresponding space maybe filled with stuffing. The stuffing may be expressed as the padding.

FIG. 40 illustrates yet another example of the BB frame structure in therelated art.

As illustrated in FIG. 40b , when the data field (alternatively,payload) of the BB frame is not fully filled with data to betransmitted, stuffing bytes may be inserted.

A STUFFI field may be inserted into the BBF header in order to signalthe stuffing bytes. The BBF header is a TS header.

The STUFFI field represents an indicator of 1 bit indicating whether thestuffing bytes are present in the BB frame.

When the payload of the BB frame is fully filled with the UP, thestuffing bytes are not present. In this case, the STUFFI may be set to‘0’.

When the payload of the BB frame is not fully filled with the UP, thestuffing bytes may be present. In this case, the STUFFI may be set to‘1’.

When the stuffing bytes are included in the BB frame, the length of thestuffing byte may be verified through a first byte of the BB framepayload.

As one example, when the first byte value of the BB frame payload is0xFF, one stuffing byte (stuffing byte of 1 byte) may be included in theBB frame payload.

When values of the first byte and a second byte of the BB frame payloadare 0xFE and 0xFF, respectively, two stuffing bytes may be included inthe BB frame payload.

Herein, when the stuffing bytes are two or more (the size of thestuffing byte is 2 bytes or more), the first and second byte values areset to MSB and LSB, respectively to signal the length of the stuffingbyte.

In a table of FIG. 36a , ‘N’ represents the total length of the stuffingbyte.

When a value of ‘N’ is 1 byte, the length of a field indicating thetotal length of the stuffing byte may be 1 byte. In this case, the fieldvalue may be set to 0xFF.

Herein, the field indicating the total length of the stuffing byte maybe expressed as a stuffing byte length field.

When the value of ‘N’ is 2 bytes, the length of the length field of thestuffing byte may be 2 bytes.

In this case, the stuffing byte length field value may be set to 0xFEand 0xFF.

When the value of ‘N’ is ‘3 or more’, as one example, even when N has avalue between 3 and 65278, the length oft eh stuffing byte length fieldmay be 2 bytes.

In this case, the stuffing byte length field may be constituted by theMSB and the LSB.

That is, the 2-byte stuffing byte length field may signal the totallength of the stuffing byte.

As illustrated in FIG. 40, additional stuffing bytes may be presentsubsequent to the MSB and the LSB. That is, since the total stuff bytelength is N and the lengths of the MSB and the LSB are 2 bytes, thelength of the subsequent stuffing byte is N−2 bytes.

FIG. 41 illustrates yet another example of the BB frame structure in therelated art.

As illustrated in FIG. 41, a 2-bit indicator may be used in order toindicate a state of the stuffing byte. The indicator may be expressed asa padding indicator (PADI).

When the stuffing byte, that is, the padding is not included in the BBFpayload (alternatively, the data field or the FEC frame), the PADI maybe set to ‘00’.

In a first BB frame illustrated in FIG. 41b , the PADI may be set to‘00’ and it may be verified that no padding in the BBF payload.

When the PADI is ‘01’, it may be represented that the length of thepadding included in the BBF payload is 1 byte.

In a second BB frame illustrated in FIG. 41b , the PADI may be set to‘01’ and it may be verified that the length of the padding is 1 byte.‘P’ which is shown represents the padding byte.

When the PADI is ‘10’, it may be represented that the padding bytes aretwo or more.

In this case, the padding field may signal the length of the padding byusing the MSB and the LSB.

In a third BB frame illustrated in FIG. 41b , it can be seen that thePADI value is set to ‘10’ and the first and second bytes of the paddingfield are allocated to the MSB and the LSB, respectively.

An additional padding marked with ‘P’ may be present subsequent to theMSB and the LSB.

FIG. 42 illustrates one example of a BB frame structure proposed in thespecification.

The specification provides the following scheme for the BB frame and theconfiguration of the BB frame header.

The BB frame may be configured to include at least one of the BB frameheader, the stuffing field, and the payload.

FIG. 42 illustrates one example of a BB frame structure in which thestuffing field is positioned ahead of the payload.

The stuffing field may be positioned subsequent to the payload in someembodiments and this will be described in detail in FIGS. 44 and 45.

The stuffing field and the payload are combined to be referred to as theBB frame payload (alternatively, the BB frame data field or FEC frame).

The BB frame header may describe a format of the payload, that is, thedata filed.

Further, information associated with a deleted null packet (DNP) or aninput stream synchronizer (ISSY) may be additionally inserted ahead ofthe stuffing field.

As described above, the payload may mean the data field.

The BB frame header may include the STUFFI field.

The STUFFI field may serve as the indicator indicating whether thestuffing bytes are present in the BB frame.

The STUFFI field may be 1 bit. In some embodiments, the position of theSTUFF1 may be changed.

As one example, when the STUFFI value is ‘0’, the BB frame does notinclude the stuffing field and may not include event he signaling field.

When the STUFFI field value is ‘1’, the BB frame may include stuffingfield or the in-band signaling field. That is, information other thanthe UP, that is, the padding or in-band field may be additionallypresent in the payload.

In some embodiments of the present invention, meanings represented by‘0’ and ‘1’ of the STUFFI value may be switched to each other.

The stuffing field may include at least one of a stuffing field headerand a stuffing data area.

The stuffing data area may include at least one of stuffing data andin-band signaling information.

The stuffing field header may be 2 bytes in some embodiments.

Further, the stuffing field header may include at least one of STUFF_ONE(alternatively, PAD_ONE), STUFF_TYPE (PAD_TYPE), and STUFF_LEN(alternatively, PAD_LEN).

A 1st byte illustrated in FIG. 42 represents a first byte of thestuffing field.

A 2nd byte may also be included in the stuffing field. In someembodiments, first two bytes (1st byte and 2nd byte) may correspond tothe stuffing field header.

In some embodiments, a third byte (3rd byte) or later may be included inthe stuffing data area or the payload.

The PAD_ONE field may be expressed as a STUFF_ONE field in someembodiments.

When the STUFFI is ‘1’, STUFF_ONE may be verified. The STUFF_ONE mayrepresent whether the length of the stuffing byte is 1 byte. TheSTUFF_ONE may be a 1-bit MSB. When the STUFF_ONE is 1, the length of thestuffing byte may be 1 byte. In this case, STUFF_LEN_LSB representingthe length of the stuffing byte may not be used.

Further, all values of STUFF_LEN_MSB may be set to 0. In this case, allvalues of STUFF_LEN_MSB may be set to 1. That is, in some embodiments,the 1-byte stuffing byte may have a value of 00000000, 11111111,10000000, or 01111111.

When the STUFF_ONE is 0, the length of the stuffing byte may be largerthan 1 byte.

In this case, the 2-byte stuffing field header may be used to representthe length and the type of the stuffing data area.

The values of the STUFF_ONE may be switched meanings to each otherdepending on the designer. That is, the meanings represented by 1 and 0may be switched to each other.

The illustrated STUFF_ONE (PAD_ONE) may be positioned at the first bitof the first byte. The position may be changed in some embodiments. TheSTUFF_ONE may be positioned at the BB frame header in some embodiments.

In some embodiments, one field of 2 bits, which serves as the STUFFI andthe STUFF_ONE may be configured in some embodiments. Since each of theSTUFFI and the STUFF_ONE is 1 bit, one field of 2 bits is configured andthe roles of the STUFFI and the STUFF_ONE may be substituted. The fieldmay be positioned at the BB frame header or in the stuffing field.

PAD_LEN may be referred to as STUFF_LEN in some embodiments. TheSTUFF_LEN may include at least one of STUFF_LEN_MSB and STUFF_LEN_LSB.

The STUFF_LEN_MSB and the STUFF_LEN_LSB may be 5 and 8-bit fields,respectively.

The STUFF_LEN_MSB and STUFF_LEN_LSB fields may be used to represent thetotal length of the stuffing field. In some embodiments, the lengths ofthe STUFF_LEN_MSB and the STUFF_LEN_LSB are switched to each other to be8 bits and 5 bits, respectively. Further, in some embodiments, thepositions of both sides may also be switched to each other. In someembodiments, the field indicating the length of the padding may bepositioned in the stuffing data area.

In the related art, the length of the padding was expressed by usingfirst 2 bytes. However, when 64K LDPC is used, the length of the paddinghas a value of maximum 6370 bytes (64 k, 5/6 code rate, BCH code).Therefore, the length of the padding may be sufficiently expressed by 13bits (2̂13=8192 bytes).

Accordingly, the PAD_LEN proposed in the specification may have 13 (5+8)bits.

When the length of the padding is expressed by 13 bits, spare 2 bits infirst 2 bytes may remain.

In the specification, a method is provided, which allocates spare 2 bitsto PAD_TYPE to signal the type when the padding area is used for anotherpurpose (for example, the in-band signaling).

STUFF_TYPE may be referred to as PAD_TYPE in some embodiments.

The STUFF_TYPE as the 2-bit field may represent the type of the stuffingdata (alternatively, the stuffing data area) as described above.

As illustrated in FIG. 38, when the STUFF_TYPE value is ‘00’, thestuffing data area may include only the stuffing data.

When the STUFF_TYPE value is ‘01’, specific-type in-band signalinginformation may be included in the stuffing data area together with thestuffing data.

When the STUFF_TYPE value is ‘10’, another-type in-band signalinginformation may be included in the stuffing data area together with thestuffing data.

When the STUFF_TYPE value is ‘11’, both the specific-type andanother-type in-band signaling information may be included in thestuffing data area together with the stuffing data.

Herein, the specific-type in-band signaling information may mean‘in-band A’ and the another-type in-band signaling information may mean‘in-band B’.

This is just one embodiment and the type indicated by the STUFF_TYPEvalue may be changed by various schemes.

Further, the STUFF_TYPE may indicate the BB frame payload and theconfiguration of the payload. For example, the STUFF_TYPE may indicatethe position of a normal first packet which is not cut in the payload.

As proposed in the specification, when the signaling is performed in thestuffing field, the in-band signaling may be inserted into a pluralityof other frames. Further, this case may be distinguished from the casein which only the padding is included without the in-band signaling.

The STUFF_TYPE may be positioned at the BB frame header in someembodiments.

Alternatively, as described in the embodiment, the STUFF_TYPE may bepositioned in the stuffing field. In some embodiments, the length of theSTUFF_TYPE may be changed.

The values of the STUFF_TYPE may be switched meanings to each otherdepending on the designer.

For example, a meaning represented by 00 and a meaning represented by 11may be switched to each other. Further, a meaning represented by 10 anda meaning represented by 01 may be switched to each other.

All of the stuffing data may have the value of 0 or 1 in someembodiments.

Hereinafter, case #1 to case #6 illustrated in FIG. 42 will be describedin detail.

(1) Case #1 illustrates a case where stuffing data and in-band signalingare not included in the BB frame.

In this case, the STUFFI field may be set to ‘0’. Accordingly, in thestructure of the BB frame, the data area, that is, the payload may bepositioned next to the BB frame header.

(2) Case #2 illustrates a case where a stuffing field of 1 byte existsin the BB frame and the in-band signaling does not exist.

In this case, the STUFFI field may be set to ‘1’. That is, the BB frameincludes a stuffing field and the stuffing field may have a size of 1byte.

Here, the first bit of the stuffing field represents a STUFF_ONE field,and has a value of ‘1’ because the size of the stuffing field is 1 byte.

The remaining 7 bits of the stuffing field may have a value of 1111111.

Accordingly, the stuffing field of 1 byte may be expressed by 11111111.

(3) Case #3 illustrates a case where a stuffing field of more than 1byte exists in the BB frame and the in-band signaling does not exist.

That is, the stuffing field may be 2 byte or larger than 2 bytes.

Since the stuffing field exists, the STUFFI field may be set to ‘1’.

The stuffing field may have the stuffing field header of 2 bytes. Thefirst bit of the first byte of the stuffing field header corresponds toa STUFF_ONE field.

The STUFF_ONE field may be set to a value of ‘0’ because the size of thestuffing field is larger than 1 byte.

The first bit of the first byte of the stuffing field header correspondsto a STUFF_TYPE field.

Since only the stuffing data exists in the stuffing data area of the BBframe, as described above, the STUFF_TYPE may have a value of 00.

In the drawing, as another exemplary embodiment, a case where theSTUFF_TYPE has a value of 11 is illustrated.

That is, this case is the case where only the stuffing data exists inthe stuffing data area of the BB frame, and the STUFF_TYPE field may beindicated as the value of 11.

Thereafter, STUFF_LEN_MSB and STUFF_LEN_LSB of the stuffing field headermay have length information of the stuffing field. As described above,the length of the stuffing field may be expressed by using a total of 13bits. After the STUFF_LEN_MSB and the STUFF_LEN_LSB, the stuffing dataarea may be positioned. In this case, only the stuffing data may bepositioned in the stuffing data area.

(4) Case #4 illustrates a case where a stuffing field of more than 1byte exists in the BB frame and the in-band signaling exists.

In this case, the stuffing data and in-band A signaling may exist in thestuffing data area of the BB frame.

The in-band A signaling may mean a specific type of in-band signalingdescribed above. In this case, because the stuffing field exists, STUFFImay have a value of 1.

The first bit of the first byte of the stuffing field header is theSTUFF_ONE field and may have a value of ‘0’ because the size of thestuffing field is larger than 1 byte.

Second and third bits of the first byte of the stuffing field header maybe the aforementioned STUFF_TYPE field.

Since only the in-band A signaling exists in the stuffing data area ofthe BB frame, as described above, the STUFF_TYPE may have a value of 10.According to an exemplary embodiment, the value may also be 01.

Next, STUFF_LEN_MSB and STUFF_LEN_LSB of the stuffing field header mayhave length information of the stuffing field. As described above, thelength of the stuffing field may be expressed by using a total of 13bits. After the STUFF_LEN_MSB and the STUFF_LEN_LSB, the stuffing dataarea may be positioned. In this case, the in-band A signaling inaddition to the stuffing data may exist in the stuffing data area of theBB frame.

(5) Case #5 illustrates a case where a stuffing field of more than 1byte exists in the BB frame and in-band B signaling exists.

In this case, the stuffing data and the in-band B signaling may exist inthe stuffing data area of the BB frame.

The in-band B signaling may mean a different type of in-band signalingdescribed above. In this case, because the stuffing field exists, STUFFImay have a value of 1.

The first bit of the first byte of the stuffing field header is theSTUFF_ONE field and may have a value of ‘0’ because the size of thestuffing field is larger than 1 byte.

Second and third bits of the first byte of the stuffing field header maybe the aforementioned STUFF_TYPE field. Since only the in-band Bsignaling exists in the stuffing data area of the BB frame, as describedabove, the STUFF_TYPE may have a value of 01. According to an exemplaryembodiment, the value may also be 10.

Next, STUFF_LEN_MSB and STUFF_LEN_LSB of the stuffing field header mayhave length information of the stuffing field. As described above, thelength of the stuffing field may be expressed by using a total of 13bits. After the STUFF_LEN_MSB and the STUFF_LEN_LSB, the stuffing dataarea may be positioned. In this case, the in-band B signaling inaddition to the stuffing data may exist in the stuffing data area of theBB frame.

(6) Case #6 illustrates a case where a stuffing field of more than 1byte exists in the BB frame and in-band A and B signaling exist.

In this case, all of the stuffing data and the in-band A and B signalingmay exist in the stuffing data area of the BB frame.

In this case, STUFFI may have a value of ‘1’. The first bit of the firstbyte of the stuffing field header is the STUFF_ONE field and may have avalue of ‘0’ because the size of the stuffing field is larger than 1byte. Second and third bits of the first byte of the stuffing fieldheader may be the aforementioned STUFF_TYPE field. Since the in-band Aand B signaling exist in the stuffing data area of the BB frame, asdescribed above, the STUFF_TYPE may have a value of 11.

In the drawing, as another exemplary embodiment, a case where theSTUFF_TYPE has a value of 11 is illustrated. That is, this case is thecase where all the in-band A and B signaling exist in the stuffing dataarea of the BB frame, and the STUFF_TYPE field may be indicated as avalue of 00.

Next, STUFF_LEN_MSB and STUFF_LEN_LSB of the stuffing field header mayhave length information of the stuffing field. As described above, thelength of the stuffing field may be expressed by using a total of 13bits.

After the STUFF_LEN_MSB and the STUFF_LEN_LSB, the stuffing data areamay be positioned. In this case, the in-band A and B signaling inaddition to the stuffing data may exist in the stuffing data area.

FIG. 43 is a diagram illustrating another example of the BB framestructure proposed in the specification.

FIG. 43A may illustrate a BB frame in the case where only the dataexists without padding, that is, the stuffing data.

STUFFI of the BB frame header may have a value of 0. A payload may bepositioned immediately after the BB frame header without the stuffingfield. The case may correspond to Case #1 of FIG. 42.

FIG. 43B may be a case of having padding of 1 byte.

In this case, STUFFI of the BB frame header may have a value of 1. Thefirst bit of the first byte may have a value of 1 as STUFF_ONE. This maymean that the padding is 1 byte. In FIG. 43, each bit of the padding mayhave a value of 11111111 (0xFF). Alternatively, according to anexemplary embodiment, each bit may have a value of 10000000. The casemay correspond to Case #2 of FIG. 42.

FIG. 43C may be a case of having padding of n byte.

In this case, STUFFI of the BB frame header may have a value of 1.Further, STUFF_ONE may have a value of 0. STUFF_TYPE may indicate thatonly the stuffing data is used without in-band signaling.

That is, according to an exemplary embodiment, STUFF_TYPE may have avalue of 00.

Next, the remaining 13 bits may indicate that the length of the stuffingfield is n bytes. The 13 bits may be STUFF_LEN_MSB and STUFF_LEN_LSB.Stuffing data may be positioned after the STUFF_LEN_MSB and theSTUFF_LEN_LSB. The case may correspond to a case where the stuffingfield is 3 bytes or more in Case #3 of FIG. 42.

FIG. 42D may be a case of having padding of n bytes in addition to thein-band A signaling.

In this case, STUFFI of the BB frame header may have a value of 1.Further, STUFF_ONE may have a value of 0. STUFF_TYPE may indicate thatthe in-band A signaling is used.

That is, according to an exemplary embodiment, STUFF_TYPE may have avalue of 01. The value itself of STUFF_TYPE may be changed as describedabove. Next, the remaining 13 bits may indicate that the length of thestuffing field is n bytes. The 13 bits may be STUFF_LEN_MSB andSTUFF_LEN_LSB. The in-band A signaling may be positioned after theSTUFF_LEN_MSB and the STUFF_LEN_LSB. The case may correspond to Case #4of FIG. 42.

FIG. 42E may be a case of having padding of n bytes in addition to thein-band B signaling.

In this case, STUFFI of the BB frame header may have a value of 1.Further, STUFF_ONE may have a value of 0. STUFF_TYPE may indicate thatthe in-band B signaling is used.

That is, according to an exemplary embodiment, STUFF_TYPE may have avalue of 10. The value itself of STUFF_TYPE may be changed as describedabove.

Next, the remaining 13 bits may indicate that the length of the stuffingfield is n bytes.

The 13 bits may be STUFF_LEN_MSB and STUFF_LEN_LSB. The in-band Bsignaling may be positioned after the STUFF_LEN_MSB and theSTUFF_LEN_LSB. The case may correspond to Case #5 of FIG. 42.

FIG. 42F may be a case of having padding of n bytes in addition to thein-band A and B signaling.

In this case, STUFFI of the BB frame header may have a value of 1.Further, STUFF_ONE may have a value of 0. STUFF_TYPE may indicate thatthe in-band A and B signalings are used.

That is, according to an exemplary embodiment, STUFF_TYPE may have avalue of 11. The value itself of STUFF_TYPE may be changed as describedabove. Next, the remaining 13 bits may indicate that the length of thestuffing field is n bytes. The 13 bits may be STUFF_LEN_MSB andSTUFF_LEN_LSB. The in-band A and B signalings may be positioned afterthe STUFF_LEN_MSB and the STUFF_LEN_LSB. The case may correspond to Case#6 of FIG. 42.

FIG. 44 is a diagram illustrating another example of the BB framestructure proposed in the specification.

FIG. 44 illustrates an example of a BB frame structure in the case wherea stuffing field is positioned at an end of the BB frame (next to thepayload).

The BB frame includes a BBF header and a BB frame payload.

The BBF header is inserted before the BB frame payload in order torepresent a format of a BBF data field.

The BBF header may have a fixed length of 2 bytes.

The BBF header includes a STUFFI field corresponding to an indicatorrepresenting whether stuffing and padding exists in the BB frame. TheSTUFFI field may be expressed by 1 bit.

The BB frame payload may include a stuffing field and a payload.

The stuffing field is included in a case where all user packets (Ups)are not filled in the BB frame payload.

As an example, when the STUFFI field is set to ‘1’, the BB frame payloadmay include the stuffing field.

The payload means an area where the UP is included.

The stuffing field may be configured by a stuffing header field(alternatively, stuffing field header) and stuffing data (area).

The stuffing data area may be expressed by the stuffing data field orthe stuffing data.

The stuffing data, in-band signaling information, and the like may beincluded in the stuffing data area.

The stuffing header field may include a STUFF_ONE field, a STUFF_TYPEfield, and a STUFF_LEN field.

The STUFF_LEN field represents a length of the entire stuffing fieldincluding the stuffing header field and may include a STUFF_LEN_MSBfield and a STUFF_LEN_LSB field. The STUFF_LEN field is expressed by 13bits.

The STUFF_ONE field means a field of 1 bit representing whether thelength of the stuffing field is 1 byte or not.

As an example, when the STUFF_ONE field is set to ‘1’, the length of thestuffing field is 1 byte. In this case, the STUFF_LEN_LSB field is notincluded in the stuffing field, that is, the STUFF_LEN field.

When the STUFF_ONE field is set to ‘0’, the length of the stuffing fieldis larger than 1 byte. In this case, 2 bytes of the stuffing header isused for representing the type and the length of the stuffing data.

That is, the STUFF_TYPE field represents the type of the stuffing dataand may be expressed by 2 bits.

The following Table 34 illustrates an example of the STUFF_TYPE field ofFIG. 44.

TABLE 34 STUFF_TYPE Stuffing Data type 00 Stuffing data only 01 IN-BANDA is used with Stuffing data 10 IN-BAND B is used with Stuffing data 11Both IN-BAND A and IN-BAND B are used with stuffing data

Referring to Table 34 and FIG. 44, when the STUFF_TYPE field is set to(1) ‘00’, the stuffing data area may be used as only the stuffing data,when the STUFF_TYPE field is set to (2) ‘01’, the stuffing data area maybe used as the In-Band A Signaling information and the stuffing data,when the STUFF_TYPE field is set to (3) ‘10’, the stuffing data area maybe used as the In-Band B Signaling information and the stuffing data,and when the STUFF_TYPE field is set to (4) ‘11’, the stuffing data areamay be used as the In-Band B Signaling information and the stuffingdata.

In Table 34, In-Band A may be In-Band-ISSY, and In-Band B may beIn-Band-PLS.

The STUFF_LEN_MSB field represents a most significant bit (MSB) value ofthe entire stuffing field length including the stuffing header field andis expressed by 5 bits.

As an example, when the STUFF_ONE field is set to ‘1’, the STUFF_LEN_MSBfield may be expressed by ‘11111’. Alternatively, the STUFF_LEN_MSBfield may be expressed by ‘00000’.

The STUFF_LEN_LSB field represents a least significant bit (LSB) valueof the entire stuffing field length and is expressed by 8 bits.

The stuffing data field may include stuffing and/or in-band signalingfield(s).

Here, the ‘stuffing and/or in-band signaling’ means stuffing, in-bandsignaling or stuffing, and in-band signaling.

That is, the expression of ‘A and/or B’ may be the same as the meaningof at least one of A or B.

Referring to FIG. 44, the eighth bit of the Nth byte of the stuffingfield represents the STUFF_ONE field, sixth and seventh bits of the Nthbyte represent the STUFF_TYPE field, first to fifth bits of the Nth byteof the stuffing field represent the STUFF_LEN_LSB field, and the N−1-thbyte of the stuffing field represents the STUFF_LEN_MSB field.

Further, the data UP, the stuffing data, the in-band A data, the in-bandB data, or the in-band A data and B data from the (N−2)th byte of thestuffing field may be represented.

A more detailed description for Case #1 to Case #6 of FIG. 44 will referto the description of Case #1 to Case #6 of FIG. 42 which corresponds toeach case of FIG. 44.

The frame structure of FIG. 44 may perform the same function as theframe structure of FIG. 42.

Like the BB frame structure illustrated in FIG. 44, when the stuffingfield is positioned at the end of the BB frame, the receiving apparatusmay directly receive the user packet (UP) without checking the stuffing,and as a result, the access time to the UP is shorter than that in theBB frame structure illustrated in FIG. 42.

FIG. 45 is a diagram illustrating still another example of the BB framestructure proposed in the specification.

FIG. 45 illustrates various BB frame structures in the case where thestuffing field is positioned at the last of the BB frame (alternatively,positioned next to the payload and the FEC frame).

Since the frame structure of FIG. 45 is different from the framestructure of FIG. 43 in only the position of the stuffing field but thesame as the frame structure of FIG. 43 in all other parts, the detaileddescription of FIG. 41 refers to FIG. 43.

FIG. 46 is a diagram illustrating comparison of a result of calculatingoverhead for transmission of a BB frame in various BB frame structures.

A graph represented by DVB-T2 may be an overhead graph in the relatedart described above. The DVB-T2 may mean a terrestrial televisionbroadcasting system-related standard of digital video broadcasting(DVB). The DVB-T2 may mean a next-generation terrestrialbroadcasting-related standard in Europe. The graph represented by theDVB-T2 may be a graph obtained by calculating the overhead in the BBframe according to this standard technique.

A graph represented by MH may be another overhead graph in the relatedart described above. The MH may mean a mobile/handheld DTVsystem-related standard of consumer electronics association (CEA). TheMH may mean a mobile handheld-related standard in North America. Thegraph represented by the MH may be a graph obtained by calculating theoverhead in the BB frame according to this standard technique.

A graph represented by SS&SN may be yet another overhead graph in therelated art described above. The SS&SN may mean one of the related art.The graph obtained by calculating the overhead when the BB frame and theBB frame header are configured by the method proposed in the related artis illustrated as the graph represented by the SS&SN.

The following Table 35 is a table illustrating a result of calculatingthe overhead upon the transmission of each BB frame.

TABLE 35 FEC 64k 16k CR 5/6 4/5 3/4 2/3 3/5 1/2 5/6 4/5 3/4 2/3 3/5 1/2Kbch 53840 51648 48408 43040 38688 32208 13152 12600 11880 10800 97207200 VB-T2 0.0297 0.0310 0.0331 0.0372 0.0414 0.0497 0.1217 0.12700.1347 0.1481 0.1646 0.2222 H 0.0019 0.0019 0.0021 0.0023 0.0026 0.00310.0076 0.0079 0.0084 0.0093 0.0103 0.0139 S&SN 0.0037 0.0039 0.00410.0046 0.0052 0.0062 0.0152 0.0159 0.0168 0.0185 0.0206 0.0278 G 0.00190.0019 0.0021 0.0023 0.0026 0.0031 0.0076 0.0079 0.0084 0.0093 0.01030.0139

The overhead may mean an overhead of a field representing a length ofthe data field.

In the related art, since a field of 2 bytes is used for each BB frame,the overhead may be a maximum of 0.22%.

In another related art, since only the field of bit is used, theoverhead may be just a maximum of 0.0139%. The overhead may be thelowest.

In yet another related art, a field of 2 bits may be used. In this case,the overhead may be two times larger than that of another related art.

A graph represented by LG may be an overhead graph according to thepresent invention. In the present invention, only the field of 1 bit maybe used for signaling of the stuffing field. Accordingly, the overheadmay be a minimum. Further, there is an advantage in that a residualfield of 2 bits is additionally prepared to be used to indicate a typeof the in-band signaling and the like. The present invention may supporta structure which is usable as other uses, such as representing aconfiguration of the BB frame, by using the residual field.

FIG. 47 illustrates one example of a BB frame structure in the relatedart.

As illustrated in FIG. 47, the BB frame includes a header, an optionalheader, and payload data.

The header includes a packet start pointer mode indicator (PSPMI) field,a padding indicator (PADI) field, and a packet start pointer lowsignificant bits (PKTSPTR_LSB) field.

The PSPMI field means a flag field having a size of 1 bit representingwhether a packet start pointer (PKTSPTR) field is a short mode or a longmode.

The PKTSPTR field may be the same concept as a SYNCD field.

That is, the PSPMI field means a flag representing whether the length ofthe PKTSPTR field is small or large.

The PKTSPTR_LSB field represents 5 LSB bits of the PKTSPTR field of 13bits.

The Optional Header may include a packet start pointer most significantbits (PKTSPTR_MSB) field and a padding field.

The PKTSPTR_MSB field represents 8 MSB bits of the PKTSPTR field of 13bits.

Further, the padding field may include a padding data length (PADL)field and a PADDING_DATA field.

The PADL field represents a length of the padding data field and has asize of 15 bits.

The PADDING_DATA field has a variable length and represents paddinginformation.

As illustrated in FIG. 47, the BB frame structure calculates the lengthof the data field in the receiving device by transmitting the length ofthe PADDING_DATA field without using information (for example, DFL)representing the length the data field, in order to express the lengthof the (payload) data field of a maximum of 13 bytes.

Here, the length of the padding field corresponds to the payload datasize of the BB frame—the length of the data field.

When the padding field does not exist in the BB frame, the data fieldlength (DFL) is calculated by using the BB frame size.

When the padding field exists in the BB frame, the PADI of 2 bits isincluded in the BB frame header to indicate the padding length.

More efficiently, in order to transmit the baseband frame (BBF) to theFEC block, that is, in order to reduce the overhead for the transmissionof the BB frame header, the PKTSPRT field is divided into PKTSPTR_LSBand PKTSPTR_MSB to operate.

That is, the PKTSPTR field can support up to the size of 2 bytes, butwhen the length of the PKTSPTR field is small (≦31 byte), only thePKTSPTR_LSB may be used, and as a result, the transmission size of thePKTSPTR field may be shortened to 1 byte.

However, since the length of the PKTSPTR_LSB is small as 5 bits, onlywhen the size of the PKTSPTR field is 31 byte or less, there is adisadvantage in that the BBF header of 1 byte can be configured.

As described in FIG. 39, the existing BB frame is used by allocating theDFL to each BB frame header in order to indicate the length of the datafield of the BB frame to the receiving device (alternatively, receivingterminal, and as a result, the overhead when transmitting the BB frameto the FEC block largely occurs.

Accordingly, a new BB frame structure for enhancing transmissionefficiency of the BB frame header and adding a new function of an errorcheck will be described in detail.

That is, this specification provides a method of entirely reducing asize of the BB frame header by controlling the size of the SYNCD fieldincluded in the BB frame header, a method of performing an error checkby using a residual 1 bit in the BB frame header, and the like.

Hereinafter, the methods and the BB frame structure proposed in thisspecification operate in a BB frame header insertion block of thetransmitting device and a BB frame deader parser block in the receivingdevice.

FIG. 48 is a diagram illustrating an example of the BB frame structureproposed in the specification.

An input stream of FIG. 48A forms a BB frame structure of FIG. 48Bthrough a mode adaptation module of an input formatting module.

As illustrated in FIG. 48, the input stream including a plurality ofpackets is sliced or mapped to the payload through the mode adaptationmodule, and a header including information on the payload is addedbefore the payload.

The payload may be expressed by a BB frame data field.

The header may include at least one of an OPTIONI field, a STUFFI field,a SYNCD_LSB field, a SYNCD_MSB field, a Checksum field, and a Stuffingfield.

As described above, the Stuffing field may include a Stuffing Headerfield and a Stuffing Byte field.

The Stuffing Byte field may be expressed by the stuffing data field orthe stuffing data area.

The BB frame header including the OPTIONI field, the STUFFI field, andthe SYNCD_LSB field may be defined, and the Option Header including theSYNCD_MSB field and the Checksum field may be defined.

FIG. 48 illustrates that the BB frame header and the Option header aredefined.

Further, the stuffing field may be included in the header or may not beincluded in the header.

When the stuffing field is not included in the header, a BB framepayload may be configured together with the payload.

The stuffing field may be positioned before the payload (FIG. 48) orafter the payload.

The SYNCD field may represent a distance from a start of the data fieldto a start of the first transmitted UP starting in the data field.

Here, the SYNCD field may be divided into a SYNCD_LSB field and aSYNCD_MSB field and has a size of 13 bits.

The SYNCD_LSB field has a size of 6 bits as a value representing the LSBof the SYNCD and may express the SYNCD of a maximum of 63 bytes.

As illustrated in FIG. 48, when the header is divided in to the BB frameheader and the Option Header, the SYNCD_LSB field may be included in theBB frame header.

Further, the SYNCD_MSB field has a size of 7 bits as a valuerepresenting the MSB of the SYNCD.

As illustrated in FIG. 48, when the header is divided in to the BB frameheader and the Option Header, the SYNCD_MSB field may be included in theOption header.

The usage of the SYNCD_MSB field is determined by the OPTIONI field.

The OPTIONI field represents whether a position of a packet which newlystarts among the packets transmitted through the payload is expressed bySYNCD_LSB of 6 bits.

As an example, when the OPTIONI field is set to ‘0’, the OPTIONI fieldrepresents that a position of a packet which newly starts among thepackets transmitted through the payload may be expressed by SYNCD_LSB of6 bits.

When the OPTIONI field is set to ‘1’, the OPTIONI field represents thata position of a packet which newly starts among the packets transmittedthrough the payload may not be expressed by SYNCD_LSB of 6 bits.

Accordingly, when the OPTIONI field is set to ‘1’, the OPTIONI fieldneeds to represent a position of a packet which newly starts in thepayload by using the SYNCD_LSB field of 6 bits of the SYNCD_MSB field of7 bits.

Here, when the SYNCD_MSB field is included in the Option header, theOption Header is include din the BB frame.

The STUFFI field has a size of 1 bit and means an indicator representingwhether the stuffing field (alternatively, stuffing byte) or the in-bandsignaling field exists in the BB frame.

The Check-sum field may be used for an error check of the BB frameheader or the OPTIONI field, with the size of 1 bit.

The Check-sum field may be included in the Option Header when the headeris divided into the BB frame header and the Option Header.

As described above, the Stuffing field includes a STUFFING Header and aSTUFFING Byte.

The SYNCD_LSB field of FIG. 48 and the PKTSPTR_LSB field of FIG. 47 maybe used as the same meaning.

Here, the size of the SYNCD_LSB field of FIG. 48 proposed in thisspecification is increased to 6 bits by 1 bit, while the size of thePKTSPTR_LSB field is 5 bits.

That is, the length of the SYNCD which may be expressed by the SYNCD_LSBfield of 6 bits becomes about two times to 63 (26-1) bytes, while thelength of the PKTSPTR which may be expressed by the PKTSPTR_LSB field of5 bits is a maximum of 31 (25-1) bytes.

That is, the case where the SYNCD_MSB field is added to the header orthe BB frame header or the Option header by controlling the size of theSYNCD_LSB field proposed in this specification is reduced, and as aresult, the overhead for the transmission of the BB frame may bereduced.

For example, it is assumed that a MPEG2-TS stream of 188 bytes istransmitted.

(1) In the case of the BB frame structure of FIG. 43, a case where onlythe PKTSPTR_LSB field is included in the BB frame header in order totransmit a TS packet of 188 bytes is included (that is, a case where thePKTSPTR length has a value of 31 bytes or less) corresponds to about16.49% (31 bytes/188 bytes).

That is, the BB frame corresponding to 16.49% includes a header having asize of 1 byte, and the BB frame corresponding to remaining 83.51%includes a header having a size of 2 bytes.

Here, the header represents a format related with the payload, and maymean the BB frame header or mean including the BB frame header and theOption header.

Accordingly, the BB frame averagely includes a header having a size of1.83 bytes.

(2) On the other hand, in the case of the BB frame structure of FIG. 48,a case where only the SYNCD_LSB field is included in the BB frame headerin order to transmit a TS packet of 188 bytes is included (that is, acase where the SYNCD length has a value of 63 bytes or less) correspondsto about 33.51% (63 bytes/188 bytes).

That is, the BB frame corresponding to 33.51% includes a header having asize of 1 byte, and the BB frame corresponding to remaining 66.49%includes a header having a size of 2 bytes.

Accordingly, the BB frame averagely includes the BB frame header havinga size of 1.66 bytes, and as a result, it can be seen that the overheadfor the transmission of the BB frame may be largely reduced as comparedwith the case of having the BB frame structure of FIG. 47.

Further, the BB frame structure of FIG. 48 may perform an additionalfunction which may detect an error for the header, by using 1 bitincluded in the Optional Header as the checksum 1 bit of the header orthe check-sum 1 bit of the OPTIONI field included in the header.

FIG. 49 is a diagram illustrating another example of the BB framestructure proposed in the specification.

The output processor of FIG. 49 implements functions, processes, and/ormethods proposed in FIGS. 50, 51, and 53 to be described below.

The BB frame structure of FIG. 49 is different from the BB framestructure of FIG. 48 in the sizes of the SYNCD_LSB field/SYNCD_MSB fieldand the position of the STUFFI field, but other parts thereof are thesame.

Hereinafter, the description for the same parts as the BB framestructure of FIG. 48 is omitted, and the different parts will be mainlydescribed.

The OPTIONI field and the SYNCD_LSB field are combined to be defined asthe BB frame header, and the SYNCD_MSB field, the STUFFI field, and theChecksum field are combined to be defined as the Option Header.

Further, the OPTIONI field, the SYNCD_LSB field, the SYNCD_MSB field,the STUFFI field, and the Checksum field are combined to be defined asone header.

In this case, the header may also be expressed by the BB frame header.

As yet another example, the STUFFI field and the checksum field may becombined into one specific field. This will be described in detail inFIGS. 50 and 51 to be described below. As illustrated in FIG. 49, thesize of the SYNCD_LSB field is 7 bits, and the size of the SYNCD_MSBfield is 6 bits.

Like FIG. 49, when the size of the SYNCD_LSB field is 7 bits, a lengthof the larger number of SYNCDs may be expressed.

That is, when the size of the SYNCD_LSB field is 7 bits, an expressiblelength of the SYCND is 127 (27-1) bytes and becomes about four timeslarger than the case (31 bytes) of FIG. 48.

Similarly, it is assumed that a MPEG2-TS stream of 188 bytes istransmitted. As illustrated in FIG. 50, the size of the SYNCD_LSB fieldis 7 bits, and the size of the SYNCD_MSB field is 6 bits.

In the case of the BB frame structure of FIG. 49, a case where only theSYNCD_LSB field is included in the BB frame header in order to transmita TS packet of 188 bytes is included (that is, a case where the SYNCDlength has a value of 127 bytes or less) corresponds to about 67.55%(127 bytes/188 bytes).

That is, the BB frame corresponding to 67.55% includes a header having asize of 1 byte, and the BB frame corresponding to remaining 32.45%includes a header having a size of 2 bytes.

Accordingly, the BB frame averagely includes a header having a size of1.32 bytes, and as a result, the overhead for the transmission of the BBframe may be largely reduced as compared with the case of having the BBframe structures of FIGS. 47 and 48.

Similarly, even in the BB frame structure of FIG. 49, the error checkfor the header may be additionally performed by using residual 1 bitexisting in the header as the Checksum (as the check-sum 1 bit of theheader or as the check-sum of the OPTIONI field.

FIG. 50 is a diagram illustrating still another example of the BB framestructure proposed in the specification.

As illustrated in FIG. 50, the aforementioned STUFFI field and checksumfield may be combined into one specific field 5010.

The specific field 5010 may be used as a value indicating whether thestuffing field is present in the BB frame.

The specific field 5010 may be expressed as an extension indicator(EXT_I) field and may have a size of 2 bits.

Further, the specific field 5010 may be expressed as an optional headerindicator (OPTI) field.

The OPTI field may mean a field indicating whether a header includingthe Stuffing is present.

The BB fame may be constituted by a header and a payload and the heardmay be constituted by one or more sub-headers.

That is, one or more sub-headers may be expressed as a first header, asecond header, a third header, and the like.

As one example, the first header may be expressed as a BBF header, abase header, or the like and the second header may be expressed as anoption header, an optional header, or the like.

The specific field 5010 may be included in the option(al) header of theBB frame.

Table 36 given below illustrates one example of a specific field (EXT_Ifield) format.

TABLE 36 EXT_I Note 00 No stuffing 01 1 byte stuffing 10 2 byte stuffing11 3~ byte stuffing

In Table 36, the specific field value of (1) ‘00’ indicates the casewhere no stuffing is present in the BB frame, (2) ‘01’ indicates thecase where the stuffing of 1 byte is present in the BB frame, (3) ‘10’indicates the case where the stuffing of 1 bytes is present in the BBframe, and (4) ‘11’ indicates the case where the stuffing of 3 bytes ormore is present in the BB frame.

As described above, the Stuffing field may include a Stuffing Headerfield and a Stuffing Byte field.

Further, the stuffing header field may include a STUFF_TYPE field, aSTUFF_LEN_LSB field, and a STUFF_LEN_MSB field.

The STUFF_TYPE field may be expressed an extension type (EXT_TYPE)field. In this case, the EXT_TYPE field may indicate a type of thestuffing field.

Further, the stuffing field may be expressed an extension field.

The STUFF_TYPE field may be included in the BB frame or the BB frameheader when the EXT_I field has ‘01’, ‘10’, or ‘11’. Detailed contentsthereof will be described with reference to Table 37 given below.

The STUFF_TYPE field may be 3 bits, the STUFF_LEN_LSB field may be 5bits, and the STUFF_LEN_MSB field may be 8 bits.

The STUFF_LEN_LSB field may be expressed as an EXT_LEN LSB field and theSTUFF_LEN_MSB field may be expressed as an EXT_LEN_MSB field.

Hereinafter, the STUFF_TYPE field and the STUFF_LEN field which may bedefined according to the specific field value, and meanings thereof willbe described with Table 37 as one example.

TABLE 37 EXT_I STUFF_TYPE STUFF_LEN description 00 Not exist Not existNo stuffing 01 000 00000 1 byte stuffing 10 000 00000 2 byte stuffing 11000 stuff_len 3~ byte stuffing 11 001 stuff_len Stuffing + mode1(ISSY)11 010 stuff_len Stuffing + mode2 (INBAND_SIG) . . . . . . . . . . . .11 111 stuff_len Stuffing + mode7(reserved)

In Table 37, when the specific field (e.g., EXT_I field) value is ‘00’,since no stuffing is present, the STUFF_TYPE field and the STUFF_LENfield are not present in the stuffing field.

When the specific field value ‘01’, the STUFF_TYPE field value is ‘000’,and the STUFF_LEN field value is ‘00000’, the stuffing of 1 byte isincluded in the BB frame (alternatively, the stuffing field).

When the specific field value ‘10’, the STUFF_TYPE field value is ‘000’,and the STUFF_LEN field value is ‘00000’, the stuffing of 2 bytes isincluded in the BB frame (alternatively, the stuffing field). When thespecific field value ‘110’, the STUFF_TYPE field value is ‘000’, and theSTUFF_LEN field value is ‘stuff_len’, the stuffing of 3 bytes or more isincluded in the BB frame (alternatively, the stuffing field).

When the specific field value ‘11’, the STUFF_TYPE field value is ‘001’,and the STUFF_LEN field value is ‘stuff_len’, the stuffing and in-band Asignaling are included in the BB frame (alternatively, the stuffingfield).

The in-band A may be the INBAND_ISSY.

When the specific field value ‘11’, the STUFF_TYPE field value is ‘010’,and the STUFF_LEN field value is ‘stuff_len’, the stuffing and in-band Bsignaling are included in the BB frame (alternatively, the stuffingfield).

The in-band B may be INBAND_SIG.

When the specific field value ‘11’, the STUFF_TYPE field value is ‘111’,and the STUFF_LEN field value is ‘stuff_len’, the stuffing and otherinformation are included in the BB frame (alternatively, the stuffingfield).

Further, the STUFF_LEN field value may be divided into a STUFF_LEN_LSBfield (5 bits) value and a STUFF_LEN_MSB field (8 bits) value.

This will be described with reference to Table 38.

TABLE 38 EXT_I STUFF_TYPE STUFF_LEN_LSB STUFF_LEN_MSB description 00 Notexist Not exist Not exist No stuffing 01 000 00000 Not exist 1 bytestuffing 10 000 00000 00000000 2 byte stuffing 11 000 stuff_len_lsbstuff_len_msb 3~ byte stuffing 11 001 stuff_len_lsb Not existmode1(ISSY) only 11 010 stuff_len_lsb stuff_len_msb Stuffing +mode1(ISSY) . . . . . . . . . . . . . . . 11 111 stuff_len_lsbstuff_len_msb Stuffing + mode8(reserved)

In Table 38, when the specific field value ‘01’, the STUFF_TYPE fieldvalue is ‘000’, the STUFF_LEN_LSB field value is ‘00000’, and theSTUFF_LEN_MSB field value is ‘Not exist’, the stuffing of 1 byte isincluded in the BB frame (alternatively, the stuffing field).

When the specific field value ‘10’, the STUFF_TYPE field value is ‘000’,the STUFF_LEN_LSB field value is ‘00000’, and the STUFF_LEN_MSB fieldvalue is ‘00000000’, the stuffing of 2 bytes is included in the BB frame(alternatively, the stuffing field).

When the specific field value ‘11’, the STUFF_TYPE field value is ‘000’,the STUFF_LEN_LSB field value is ‘stuff_len_lsb’, and the STUFF_LEN_MSBfield value is ‘stuff_len_msb’, the stuffing of 3 bytes or more isincluded in the BB frame (alternatively, the stuffing field).

When the specific field value ‘11’, the STUFF_TYPE field value is ‘001’,the STUFF_LEN_LSB field value is ‘stuff_len_lsb’, and the STUFF_LEN_MSBfield value is ‘Not exist’, only the in-band A signaling is included inthe BB frame (alternatively, the stuffing field). Preferably, only thein-band A signaling is included in the stuffing field only when thein-band A signaling may be expressed by 32 bytes. The in-band A may bethe INBAND_ISSY.

When the specific field value ‘11’, the STUFF_TYPE field value is ‘010’,the STUFF_LEN_LSB field value is ‘stuff_len_lsb’, and the STUFF_LEN_MSBfield value is ‘stuff_len_msb’, the stuffing and the in-band A signalingare included in the BB frame (alternatively, the stuffing field).

When the specific field value ‘11’, the STUFF_TYPE field value is ‘111’,the STUFF_LEN_LSB field value is ‘stuff_len_lsb’, and the STUFF_LEN_MSBfield value is ‘stuff_len_msb’, the stuffing and other information areincluded in the BB frame (alternatively, the stuffing field).

FIG. 51 is a diagram illustrating still another example of the BB framestructure proposed in the specification.

In FIG. 51, as a method associated with a use method of the STUFF_TYPEfield, a method is provided, which divides and uses the 3-bit STUFF_TYPEfield into a 1-bit MSB indicator (MSB_I) field 5111 and a 2-bitSTUFF_TYPE field 5112 for efficient use.

The MSB_I field 5111 represents an indicator that indicates whetherSTUFF_LEN_MSB field is present.

As one example, when the MSB_I field value is ‘0’, this value mayindicate that only SUTFF_LEN_LSB (5 bits) is used in the stuffing headerand when the MSB_I field value is ‘1’, the value may indicate that theSTUFF_LEN_LSB (5 bits) field and the STUFF_LEN_MSB (8 bits) are used inthe stuffing header 5110.

As one example, when the MSB_I field value is ‘0’, only theSTUFF_LEN_LSB (5 bits) field is used (alternatively, included) in theSTUFFING header and the size of the stuffing field which may beexpressed is 32 bytes.

When the MSB_I field value is ‘1’, the STUFF_LEN_LSB (5 bits) field andthe STUFF_LEN_MSB (8 bits) field are used (alternatively, included) inthe STUFFING header and the size of STUFF_LEN which may be expressed is13 bits.

Next, the STUFF_TYPE field (2 bits, 4712) indicates a use type of thestuffing field.

On example of the STUFF_TYPE field may include ISSY, in-band signaling,and the like.

The STUFF_TYPE field indicates a stuff type designated so that thestuffing field interval is used for other purposes (e.g., in-bandsignaling and in-band ISSY).

Meanings of the MSB_I field and the STUFF_TYPE field newly defined witha size of 2 bits will be described in more detail with reference toTable 39 given below.

TABLE 39 EXT_I MSB_I STUFF_TYPE STUFF_LEN_LSB STUFF_LEN_MSB description11 0 00 stuff_len_lsb Not exist reserved 11 1 00 stuff_len_lsbstuff_len_msb 3~ byte stuffing(stuff_len) 11 0 01 stuff_len_lsb Notexist In-band ISSY table + stuffing(size ≦32 Bytes) 11 1 01stuff_len_lsb stuff_len_msb In-band ISSY table + stuffing(size >32Bytes) 11 0 10 stuff_len_lsb Not exist In-band PLS table + stuffing(size≦32 Bytes) 11 1 10 stuff_len_lsb stuff_len_msb In-band PLS table +stuffing(size >32 Bytes) 11 0 11 stuff_len_lsb Not exist Reserved mode +stuffing(size ≦32 Bytes) 11 1 11 stuff_len_lsb stuff_len_msb Reservedmode + stuffing(size >32 Bytes)

In Table 39, when the STUFF_TYPE field value is ‘00’, the valueindicates a case in which the stuffing field is constituted by onlystuffing bytes and when the STUFF_TYPE field value is 01, 10, and 11,the values express respective modes used for different purposes in thestuffing field.

As illustrated in FIG. 51 and Table 39, in the case where both the MSB_Ifield and the STUFF_TYPE field are used in the stuffing header, when thesize of the sum of ISSY and stuffing in the stuffing field is 32 bytesor less, since the stuffing header does not include the STUFF_LEN_MSBfield, 1-byte overhead may be reduced.

When the size of the sum of ISSY and stuffing in the stuffing field islarger than 32 bytes, the MSI_I field may be set to (alternatively,marked with) ‘1’ and the STUFF_LEN_MSB field may be used in the stuffingheader.

FIG. 52 is a flowchart illustrating one example of a method fortransmitting a broadcast signal proposed in the specification.

Referring to FIG. 52, the broadcast signal transmitting apparatusproposed in the specification processes input streams through an inputformatting module (S5210). That is, the broadcast signal transmittingapparatus formats the input streams with multiple data pipes (DPs) inthe in put formatting module.

In detail, the broadcast signal transmitting apparatus allocates datapackets to a payload of the baseband frame (BBF) and adds a headerindicating a format for the payload of the baseband frame, for the inputformatting in S5210.

The data pipes (DPs) can be represented to data transmission channels.

The header may include the EXT_I field and the stuffing field asillustrated in FIGS. 50 and 51.

The EXT_I field means a field indicating whether the stuffing field ispresent in the BB frame and may have a size of 2 bits.

The stuffing field includes the stuffing header and the stuffing headerincludes the MSB_I field and the STUFF_TYPE field.

The MSB_I field represents an indicator that indicates whether theSTUFF_LEN_MSB field is present and may have a size of 1 bit.

Further, the STUFF_TYPE field means a field that indicates the use typeof the stuffing field and may have the size of 2 bits.

The EXT_I field, the MSB_I field, and the STUFF_TYPE field may be usedas an expression of control information so as to be applied to otherexemplary embodiments.

Thereafter, the broadcast signal transmitting apparatus encodes data ofmultiple (formatted) DPs for each DP through a bit interleaved codingand modulation (BICM) module (S5220).

The bit interleaved coding and modulation (BICM) module can berepresented to a encoder.

Thereafter, the broadcast signal transmitting apparatus maps the encodedDP data through a frame building module to generate at least one signalframe (S5230).

The frame building module can be represented to a frame builder.

Thereafter, the broadcast signal transmitting apparatus modulates dataof the generated signal frame an orthogonal frequency divisionmultiplexing (OFDM) generation module by an orthogonal frequencydivision multiplexing (OFDM) scheme and transmits a broadcast signalincluding the modulated data of the signal frame (S5240).

FIG. 53 is a flowchart illustrating one example of a broadcast signalreceiving method proposed in the specification.

Referring to FIG. 53, a broadcast signal receiving apparatus receives abroadcast signal from the outside through a synchronization anddemodulation module and demodulates data by an OFDM scheme with respectto the received broadcast signal (S5310).

The synchronization and demodulation module can be represented to areceiver and a demodulator.

Thereafter, the broadcast signal receiving apparatus parses thedemodulated data to at least one signal frame through a parsing module(S5320).

The parsing module can be represented to a frame parser.

Then, the broadcast signal receiving apparatus decodes at least oneparsed signal frame into multiple DPs through a demapping a decodingmodule (S5330).

The demapping and decoding module can be represented to a converter anddecoder.

Thereafter, the broadcast signal receiving apparatus restores themultiple data pipes output from the demapping and decoding module toinput streams through an output processor module.

The broadcast signal receiving apparatus decodes information transmittedto a header of the baseband frame through a baseband frame processorblock and restores the input streams by using the decoded information,for the output processing in S5340.

The header may include the EXT_I field and the stuffing field asillustrated in FIGS. 50 to 52.

The EXT_I field means a field indicating whether a stuffing field ispresent in a BB frame and may have a size of 2 bits.

The stuffing field includes a stuffing header and the stuffing headerincludes an MSB_I field and a STUFF_TYPE field.

The MSB_I field represents an indicator that indicates whether aSTUFF_LEN_MSB field is present and may have a size of 1 bit.

Further, the STUFF_TYPE field means a field that indicates a use type ofthe stuffing field and may have a size of 2 bits.

The EXT_I field, the MSB_I field, and the STUFF_TYPE field may be usedas an expression of control information so as to be applied to otherexemplary embodiments.

It will be appreciated by those skilled in the art that various changesand modifications of the present invention can be made without departingfrom the spirit or scope of the present invention. Accordingly, it isintended that the present invention includes the change and modificationof the present invention provided in the appended claims and a rangeequivalent thereto.

In the specification, both the inventions of the apparatus and themethod are mentioned and descriptions of the apparatus and methodinventions may be applied to be complementary with each other.

In the specification, methods and apparatuses for receiving andtransmitting a broadcast signal are used.

What is claimed is:
 1. A method for transmitting a broadcast signal, themethod comprising: formatting input streams into multiple datatransmission channels; encoding data corresponding to each of datatransmission channel carrying service data or service component data;building at least one signal frame comprising the encoded data;modulating the at least one signal frame by an OFDM (orthogonalfrequency division multiplexing) scheme; and transmitting the broadcastsignal comprising the at least one modulated signal frame, wherein theformatting comprises adding a header indicating a format of a payload ofa baseband frame (BBF), and wherein the header comprises a controlinformation indicating whether a stuffing field is present in theheader.
 2. The method of claim 1, wherein the header comprises at leastone of indication information indicating whether a most significant bit(MSB) part of a stuffing length is present in the stuffing field or astuffing type (STUFF_TYPE) field indicating a type of stuffing data. 3.The method of claim 2, wherein: the stuffing field includes a stuffingheader and stuffing data, and the indication information and thestuffing type field are included in the stuffing header.
 4. The methodof claim 2, wherein: the size of the indication information is 1 bit,and the size of the stuffing type (STUFF_TYPE) field is 2 bits.
 5. Themethod of claim 3, wherein: the stuffing header further comprises astuffing length (STUFF_LEN) field indicating the length of the stuffingfield, and the stuffing length (STUFF_LEN) field is divided into a MSB(STUFF_LEN_MSB) part of the stuffing length and an LSB (STUFF_LEN_LSB)part of the stuffing length.
 6. The method of claim 2, wherein: thecontrol information is an extension indicator (EXT_I) field, and theindication information is an MSB_I (indicator) field.
 7. The method ofclaim 1, wherein the stuffing field is included in the baseband framewhen the payload is not filled with a data packet or in-band signalingis used.
 8. The method of claim 2, wherein the stuffing data indicatesat least one of stuffing or in-band signaling.
 9. The method of claim 1,wherein when the length of the stuffing field is 32 bytes or less, theMSB (Most Significant Bit) part of the stuffing length is not includedin the stuffing field.
 10. An apparatus for transmitting a broadcastsignal, the apparatus comprising: an input formatter for formattinginput streams into multiple data transmission channels; an encoder forencoding data corresponding to each of data transmission channel whichcarrying service data or service component data; a frame builder forbuilding at least one signal frame comprising the encoded data; amodulator for modulating the at least one signal frame by an OFDM(orthogonal frequency division multiplexing) scheme; and transmitter fortransmitting the broadcast signal comprising the at least one modulatedsignal frame, wherein the input formatter comprises a baseband frameheader inserter for adding a header indicating a format of a payload ofa baseband frame (BBF), and wherein the header comprises a controlinformation indicating whether a stuffing field is present in theheader.
 11. The apparatus of claim 10, wherein the header includes atleast one of indication information indicating whether a mostsignificant bit (MSB) part of a stuffing length is present in thestuffing field or a stuffing type (STUFF_TYPE) field indicating a typeof stuffing data.